You know this is a good point, just because you can do this doesnt mean you should. Like why not use Niagara saving Chaos/PhysX for the most gameplay relevant things. Even then collision needs to be a controlled environment, games which allow players to really go nuts with physics objects tend to have strict limitations to make sure unwanted scenarios dont arise as it can quickly get out of control.
Im still seeing ragdolls glitch out in competeting engines, stuttering objects, slingshots into orbit and all the other fun things. If youre making a racing game then perhaps having Chaos being open and something you can easily modify the core of is better than PhysX where its blackboxed away in another package. Its not like you cant stick with PhysX for now, UE5 is not production ready and Epic have made that pretty clear so its super odd people are acting like Chaos needs to be finalized right this moment.
I do think you have a solid point iniside that we should be focusing on real world use cases! We should be giving Epic hard data on what to improve, what hardware configurations might be having particular issues if any, thats how things improve, a few gifs prove about as much as any synthetic benchmark. We need to be testing for viable scenarios not every what-if, especially those which purposelly exploit known weaknesses in systems. Maybe part of the issue is people are just not well versed enough with the new tools to really run them through their paces because they require a different mindset.