I find the main thing that’s important for gaming is having the latest kernel and drivers - for me with AMD, that means the open-source mesa ones. Pop! is excellent for having the cutting-edge version of these, Arch is superb, but really, that’s not much to quibble about, they’re both very good choices.

I’d rate these as ‘why Arch is better than Pop!’ for gaming; note that they are all pretty minimal improvements:

• doesn’t install anything you don’t want it to. The Arch ‘installer’ is basically a utility script that installs the packages you’d like on your new instance - doesn’t even include the kernel, in case you’re intending to run containerised. That’s not very friendly, but it does mean that I know what every running service does, because I chose to install it myself. It’s exactly the way I want it. That may matter to you for a gaming machine.

• I’ve some slightly weird USB audio on my main machine; PipeWire supports it better than PulseAudio. Arch doesn’t include either by default, so I don’t have to uninstall Pulse to install something else.

• similarly, I don’t like Gnome3, so I don’t have to uninstall it to install Cinnamon - Arch defaults to ‘neither’.

• utterly superb documentation.