Ubuntu

it also really depends. are you going to see a performance increase on LInux over Windows? sure, slightly but again that depends on what you're playing. for example I play EVE Online. Like it or not on Windows with multiple clients it just performs better. and if you know EVE you know you do need to run multiple clients to get anything done. I've tried it on virtually all Linux Distros and still to this day it still performs better and more smoothly on Windows.

that being said If I was playing something like Cyberpunk 2077 I'd play that on pretty much any linux distro over Windows. and then when it comes to which distro at this point it really doesn't matter. Will you get a slight increase on CachyOS over others? sure. but it's slight and not that noticeable. Add to the fact you can pretty much replicate what Cachy does on just regular Arch or even NixOS. same deal with something like PikaOS. will you get an increase on that over say Debian or Ubuntu. sure...but ever so slightly.

What's MORE important now is what DE/WM you're using. that's where you're going to see better performance. for DE's it's KDE hands down. for WindowManagers? surprisingly I've had abetter experience with gaming on DWM than any other. I've had mouse capture issues on Niri and Hyprland or refocus issues. Sway works well also.

So it really depends on what you're playing. I daily drive OpenBSD where yeah, no gaming there, and then I have another drive that has Windows with an Arch install on WSL2. I'm at the point now in my 40s where I just don't care anymore for the whole "this is better than that and if you use that you're lame" mentality. I just want things to work.