I agree. Vehicle sound effects are probably my biggest source of shame when it comes to the sounds in Satisfactory.
A lot of it comes to down to how difficult vehicle sounds are to implement. If you use sound samples with ramping rpms (as i do in satisfactory) you run the risk of your perceived speed and the sound you are hearing will mismatch. Engine only know's if you are going forward basically, and will just ramp through it's sounds even though you are slowly moving up a hill for instance.
Another way to do this is to bind pitch to speed on a static RPM, this is what a lot of games used to do. It conveys speed, but sound quality is usually awful, with a lot of artifacts.
What they do in AAA is that they write or buy a granular synth implementation for vehicle sounds. This is the only solution, in my mind, that would generate a good enough result. But sadly i don't see that happening in the near future.
I'll try to get some time to go over the implementation again and see if I can hammer our some of the immediate problems - but a major overhaul is not currently planned I'm afraid.