why should I use FNEI now that 2.0 added factoriopedia which allows me to see all recipes, and asteroid spawns. what tiles spawn what and with what frequency

FNEI is almost as old as the base game itself. you don't have to use it.

@Walksanator if you enjoy eating plain bread, that's totally fine, but I just prefer my bread with some toppings ;-)

I like it and we need Recipe Book too

Recipe Book is another construction site, but it should be published in the foreseeable future
you can get a version from github: https://github.com/raiguard/RecipeBook/tree/v4.0

@Walksanator if you enjoy eating plain bread, that's totally fine, but I just prefer my bread with some toppings ;-)

But what are the toppings? Seriously, though, I think the mod description could benefit from highlighting the differences between it and Factoriopedia. I was wondering what the differences are myself. Easy enough to install and poke around, though.

It doesn't have to be FNEI, every other tool has toppings too. but the best thing is that you can make the toppings yourself and at least have someone who can do it faster than Wube can make the same changes in the base game, if they even want to.

And what are those toppings? Can You list them? Any EXAMPLE? [and no "every other tool has toppings" does not count as 'example'].

RecipeBook seems to be functionally identical to factoriopedia, with only claim being 'advanced filtering options' which are not listed whatsoever, but this is not a topic about RecipeBook, but about FNEI.

Here is my claim - FNEI is actually WORSE than built-in factoriopedia.

Case in point:
Express Transport Belt [Green belt, if You prefer] - craft information.

FNEI lists ingredients [including crafting time], where it is made [YAY, only 'advantage' over built-in variant- it calculates automatically what crafting time is.... which will be incorrect as soon as You add modules/beacons to the equation], what tech is needed and what is the result of recipe.

Great. The problem?
Factoriopedia lists all the above [with caveat of not calculating the craft time per-structure], but also includes such information as: what is the recycling process of the item [which is NOT listed in 'usage' of FNEI], as well as such useless information as 'what are crafting environment requirements'. As in - where can it be built.

If You use FNEI alone You will NOT see that Green Belts are craftable only on Vulcanus [or planets modded to the needed pressure requirements].

Let us take another example:
Rocket Fuel - FNEI will show total of 6 uses of this item in modded environment - Rocket parts, nuclear fuel, incineration [removal], alternate rocket part recipe, and 2 more modded items that take it as a recipe.

What it DOESN'T show, outside of recycling that I mentioned before is another piece of 'useless' information as "Where this specific fuel can be used".

Filtering options, if FNEI has any mod-specific search options - are also not listed, making the search option also practically identical to that of factorio's baseline search.

TL:DR:
While I acknowledge FNEI's history, and usefulness in the past, in modern day FNEI seems to be waste of time, memory and space, and frankly - unless some functionality difference is created or listed, FNEI deserves to leave on its well-earned rest.
Calling it 'bread with toppings' as compared to modern day Factoriopedia would work only, if the 'topping' is excrement [or other detrimental ingredient], due to difference in functionality as listed above.

Edit: Quick caveat; Calling the 'topping' an extrement is in no way intended as an insult to npo6ka, or the FNEI itself, especially as back in the day FNEI filled quite important hole in Factorio's design, UI and user friendlyness, it IS intended as an insult to condescending way kuxynator answered the original question, without providing any factual details.

the factual detail you have overlooked is the expandability .

you did not understand what i meant. it was not about which exact feature is included, or how good it works, but the possibilities to add additional features, i.e. every mod is more flexible than the factoriopedia. you would need an extremely good api if Wube wanted to make it possible to customize the factoriopedia. and as long as that does not exist, only mods remain. Regardless of which one and how well they do it.
Recipe Book, for example, is also “only” a visual copy of the factoriopedia (at least for now). but it is the basis for extensions. Whether someone prefers an FNEI GUI or a factoriopedia GUI is more a question of UX.

BTW one feature is to have a single click to build the factory and don't have to start looking for the machine in the crafting menu, find and craft parts, build it and then have to search for the recipe in the factory again.

P:S: I never said that FNEI is perfect or that you never need factoriopedia. but if you compare exactly the current version of FNEI with the current factoriopedia, some information is missing in FNEI. but it never stopped me personally from using FNEI and ignoring factoriopedia for a long time ;-) The code of FNEI is better built from a developer point of view than other “tinkered” mods, it just needs time for a renovation of UI and displayed data in the meantime but no one can be blamed if there is no time for it.

I have ignored expandability on purpose. While it is indeed a nice feature to have, it is functionally useless when no other mod used it to expand upon, unless you are mod developer yourself.

To put it into perspective - You can have foundation capable of supporting entire skyscraper, if someone were to build one there, though as long as there is only a single-story house, most this foundation is at best overengineered for its use or outright useless.

Keep in mind - it still is useful for builders/architects/engineers [think - mod developers], but at the same time completely useless in its function for just a tenant [user] of building [mod] that is there [current form] who has no intent to build anything bigger [their own new mod based on current one] or expand existing building [their own tinkered variant of the mod].

The degree to which FNEI is currently improving expandability of existing feature [Factoriopedia] is debatable, given high degree of native moddability of Factorio itself [as opposed to e.g. most Unity games which may require injector to modify anything, including an UI element], though admittedly it is a completely irrelevant discussion, so if You excuse me - I will ignore it, and simply assume You are right and FNEI is much more expandable than Factorio's native Factoriopedia.

Here's the problem however - FNEI is not listed as modding library mod. If it was - You'd be fully correct that expandability upon which one can build further mods is critical, HOWEVER FNEI is not a modding library mod. It is Utility Mod, with intent to provide information regarding recipes and use of items
"This mod will help you find all the recipes to create the selected item.
Also you can see the use of the selected item."

In that role, while historically it was a mod that was almost instant-inclusion for any modded playthrough (depending on Factorio version), currently its utility in stated function lags behind built-in solution, specifically due to missing information.

While I am willing to acknowledge biggest advantages of FNEI over Factoriopedia - specifically its data persistence [specifically - keeping the selected item's information pre-selected when reopening the menu], smaller window size, and quick-selection menu; the ability to copy a facility that produces the item in question into selection is not something unique [pipette tool, Q by default, is extremely versatile]. It might be however the issue of there being a control option that would copy both the facility and the correct recipe, that I am unaware of, and is not listed in mod's instructions.

RecipeBook, while functionally intended to fill the same niche is a topic I have no intent of digging into in the topic of uses of FNEI, I hope You will excuse me for that. It does seem to suffer similar issue of FNEI, as in - lack of other 'extensions' over existing foundation.

Now, don't get me wrong - FNEI is not a bad mod, and especially the old guard will prefer it over Factoriopedia (partially due to remembering the planet limitations by heart, partially because some people know where to find it, and partially due to being grandfathered into FNEI, due to past experience, and partially due to the quality of early versions of Factoriopedia), I'm not sure if I'd recommend FNEI for a new player, who may not have any intent to build upon existing foundation or updating it, unless they need a small scale window kept running while working.

Admittedly, primary reasons for my initial antagonism towards Your statement were twofold:
1 - Your focus on perspective of mod developer, and not a (functionally random) player, with unknown skill level.
2 - The manner of Your response, which rather than address the question directly (in this case - persistence of last query, smaller 'footprint' of the window), compared FNEI to sandwich with topping, which I found extremely jarring given information discrepancy between FNEI and Factoriopedia.

With that out of the way - I hope we will at least be able to agree on the following comparison which to select [Factoriopedia VS FNEI] from perspective of user with no ingrained reflexes regarding UI [and sure as death and taxes any longer-term player will have them, especially when moving first time from 1.1 and earlier to 2.0]:
- IF You want more comprehensive data on recipes, including any and all limitations and recycling information of the item - go with Factoriopedia.
- IF You want a handy note-book style recipe book to keep on hand while working - FNEI could be a good alternative, provided You get used to a little different and admittedly - slightly old style, UI.

LOL I don't even know what you want, it's too much effort for me to translate it all. sry ;-)
What exactly do you want to achieve? To convince users to stop using FNEI. To kill every argument in favor of using it? or are you just slightly off the point now? or am I completely misunderstanding you. then sorry, English is not my first language.

why should I use FNEI now that 2.0 added factoriopedia

meant to me that OP don't know what he should still use it for.
a) don't use it anymore
b) let yourself be convinced to still use it,, what I did
c) don't have to convince anyone that you don't want to use it ;-)
and i don't have to try to convince anyone either. have fun :-)

EDIT: my point of view is: mods can be extended (or forked and improved) by anyone, with Factorio itself, only the developers can do that.

I will be blunt.
Either:
A) Learn English to better degree read the answer You want to respond to OR
B) Get a translation software for that (heck, even ChatGPT seems to work rather well) OR
C) Do not answer a comment You didn't bother to read for any reason.
Just for the record: I am not a native English speaker either.

While I agree with the purpose of OP's question, I was under the impression, given the further part of the question You omitted:

which allows me to see all recipes, and asteroid spawns. what tiles spawn what and with what frequency
that OP was interested in functionality difference between Factoriopedia and FNEI. With that context, Your statement about "bread with toppings" would imply, for most English speakers, that FNEI has those 'toppings' - i.e. additional features.

Here we go to my original purpose:
Dispute of Your implied claim ["I prefer bread with toppings"] that FNEI is better due to "toppings", or additional features. In Your later statement - main would be expandability [which would be as far from 'toppings' as possible]. It is not a notable feature of FNEI, and why I think so is listed in previous comment of mine [Most of my previous comment was related to expandability feature's role in stated mod purpose].

As per Your edit: I find it absolutely HILARIOUS that Your claim of "Factorio not being able to be extended, or forked and improved" relies specifically on claim of editing of existing files, rather than modifying them by appending code, while mods are doing just that: change how Factorio works, either extending it [content addons], improving it [UI mods]. or removing stuff from it [alternate-mechanics mods, which may e.g. remove features that Factorio has by default, such as drone fuel use]. It is doubly funny coming from You, who is a mod creator last time I checked [love Your Ion Cannon mod by the way], on a discussion on a mod that expands upon Factorio's UI, and has expanded for quite some time, even though UI is stylistically different from current Factorio's UI.

From our exchange it seems like the biggest issue in this exchange is Your apparent misuse of comparison/idiom of 'bread with toppings'. Usually "Bread with toppings" as opposed to 'Plain Bread' means existing additional elements in the former. It is plain bread that can be most customized after all, as no topping will interfere with any other.

With that out of the way - thank You for exchange, and have fun around :)

You replied to my post — not the other way around! Judging by the wall of text, you probably enjoy hearing yourself talk. Telling me to improve my English is a bit cheeky — I just didn’t feel like reading essays where the effort isn’t worth the benefit. I could just as well tell you to learn programming. I don’t see any mods from you here. But since I know people have different priorities, I won’t go there.

As far as I’m concerned, this discussion is over — I’ve got better things to do.
Apologies to anyone who was bored, and you’re welcome to those who enjoyed the show. 😄
- Enough English practice for today - it was a pleasure -

Yes, I did respond to Your post. Your comment however was to my response that You did not read. That are YOUR words.

Rather than 'enjoy hearing myself talk', unlike You - I use arguments and explanation to my points. And I address points the other side makes directly, rather than making assumptions.

As per programming - You'd shoot and miss, I am a programmer. Me not making any mod for Factorio doesn't change that fact (especially when we take into account that lua is primarily scripting language, which is not first choice for stand-alone applications), but I digress.

And yes, I DID tell You to improve Your English OR not answer to statements You didn't bother to even read. Mostly because of Your own statement - that Your English was insufficient to bother to read my post fully without much effort:

LOL I don't even know what you want, it's too much effort for me to translate it all. sry ;-)

Specifically - the recommendation for English improvement was for You to read what You respond to, and not misrepresent the other side's stance. That happens to be bare minimum in discourse I am used to, though admittedly - expecting bare minimum academic discourse standards [listening and understanding the whole point of the other side, rather than just part of it] might be too much in mod discussion. You also ask questions, You'd KNOW the answer to, as well as my reasoning for not including part of it, if You bothered to read the answer. IF reading the other side is 'too much effort' - why bother answering in the first place? [And yes, that's a rhetorical question].

Either way - I agree, this exchange is fundamentally over, though frankly - I don't think I'd call it proper discussion in the first place.
Have a great day.

To anyone else who wants TL:DR - this is my answer to OP's question, with a small commentary edit from original statement few posts back:

• IF You want more comprehensive data on recipes, including any and all limitations and recycling information of the item - go with Factoriopedia, keep in mind it might be a bit unwieldy when using due to size.
• IF You want a handy note-book style recipe book to keep on hand while working- FNEI could be a good alternative, provided You get used to a little different and admittedly - slightly old style, UI, and keep in mind not everything can be built everywhere.

P.S. Added an explanation to LUA part. On note related to the exchange - I do find it quite hilarious in hindsight that I have ran into mods... Modyfing Factoriopedia, but none of mods that modify FNEI as addons, aside of a single fork. Either way - keep up the good work npo6ka.

Sheesh. does Wube police these comment sections?
If kuxynator needs lessons in English, then Eurannnon needs lessons in manners.