I mean…
Steam? Maybe? I dunno, I don’t game but the Steam kids seem to prefer Arch. I’m sure they have their reasons.
Practically? Probably nothing terribly significant.
I’m a complete noob in the games department. Btw, I see that you don’t use Arch.
Reasons are usually just newest kernel/mesa/etc. Most of the time the difference is very small, and often inconsequential. However, every now and again there is a major development that might make it worth it (IE: The graphics pipeline that all but made dxvk-async obsolete)