As others have said I doubt you will see a difference but I can attest to arch working just fine for gaming. Between steam and Lutris I haven't run into any real issues.
So if you're wanting to try arch go for it with confidence that your gaming experience likely won't be impacted.
Yea it hasn't disappointed me so far, I'm also still in the trial, been waiting for a search that turns crap results on G and DDG to try and put it through the paces. Though compared to G it is nice not having half the results be sponsored.