It used to be really bad this spring, but now it's somewhat buggy but fundamentally fine. Somewhere around March games would just randomly lose focus, start stuttering, or you couldn't use fullscreen while having a secondary monitor connected, that sort of thing. Now it's mostly fine. Steam Remote Play still has issues, but this is really a niche use case.
I've been running the 6.16 kernel via mainline for a couple months and that has taken care of most of my issues with games, running ta current gen AMD gpu. Can't speak for how much of the stability increase has been the kernel vs the DE though, just been getting more solid along the way. I just switched about 5-6 months ago though.
