by that logic you also have to add Manjaro to Arch at 2.95% which makes it 51.65% Arch, plus I use EndeavorOS which is also based on Arch and not on the list, but I would not be surprised if it broke the 1% userbase for steam.
From the 22% Other: We probably have at least 5% Red Hat based distros like Fedora and Nobara that I hear is popular for gaming.
2-3% might be OpenSuse
Big fan of Nintendo's classic 1985 single, "It's a me, Mario"