I did the math, and advanced oil processing then cracking gives 87 petroleum gas per 100 crude, as opposed to 90 from basic processing.
So, unlike in regular Factorio, basic processing doesn't become obsolete the moment you unlock advanced processing.
However! That's if you don't use productivity modules, and the important thing to remember about productivity modules is that adding more processing steps makes them exponentially better for resource efficiency.
If you're using two productivity 3 modules for each step (a likely configuration if you're in the early space stage and using beacons), for a 1/2/3 step process you get 16%/34.5%/56% more output for your initial input.
Basic oil processing is a 1 step process, so you only get a 16% bonus.
Advanced oil processing plus cracking is a mix of 1, 2, and 3 step processes to get gas, most of it coming from the 2 step process, so it's roughly a 34.5% bonus.
Factoring in the bonuses assuming it's 16% for each step, you're getting:
104.4 gas per 100 crude with basic processing
Roughly 117 gas per 100 crude with advanced processing
As you get better productivity modules, the advantage of advanced processing will keep growing.
So, it all comes down to what you want to optimise, whether you want an oil industry that relies on cracking.
Use mostly basic processing if you want stuff to be simpler and cheaper to build and to minimise the land, energy, and pollution footprint of your oil processing.
Use entirely advanced processing if you want resource efficiency above all else, with a small advantage at first that grows as you progress through the tech tree.
Personally I go for the advanced processing. I'm using Rampant which means I need to put a lot more work into protecting any mines (so I want to use oil as efficiently as possible), plus the energy demands are trivial to meet, and since I'm placing all the oil processors and crackers in a line away from my factory the land footprint isn't an issue.
