Tumbleweed vs Windows 11 in 5 games on a 3080M - Windows about 10% faster on Average
(video.hardlimit.com)
Of course I can't entirely generalize from this, however my 2080Ti worked perfectly out of the box on EndeavourOS. Game performance is also mostly similar to my Windows install - if they ran well, they still do, and if they ran badly, then the same goes for that as well.