I just recently made to switch to base Arch from Cachy so I can run Omarchy without any issues and it did take several hours of extra setup just to have a working system but it is nice knowing how to do it now.
In terms of benchmarks, gamers tend to care more about consistent responsiveness (and worstcase performance) than raw throughput. Phoronix benchmarks are probably not the best way to compare CachyOS against other distros. E.g., look at the game benchmarks you linked: all tested games were already running above 500 frames per second in the worst performing game.
Steam doesn’t need weekly rolling updates, and I got sick of diagnosing random regressions in basic functionality.
Also, since basic stuff doesn’t require multiple app stores and a byzantine systemd stack, it’s much easier to understand and debug.
I certainly wouldn’t give that up for a 6% improvement in mean frame rates.