There are distributions with a great Steam experience out of the box? It's SteamOS actually a good choice? Maybe isn't what you use or prefer.
A good Steam distro for me has a very mininal procedure for perfectly working controllers, client and general user experience.
Your direct test and experience are very appreciated.
Newer GPUs are fine in Wayland. I have a 3090 and Wayland is the only way I can get full refresh rates on all my monitors because X locks you to the lowest value. Only thing is that the translucency on themes doesn't render super well and sometimes the system clock and taskbars will freeze up. That aside, it's been a good gaming experience overall.