Smaller more specific distros like Nebara may sound good, but if there are issues, you will have to wait a long time for a small team to fix them, or work it out yourself.
All standard distros can be used for gaming, you may need to find a way to pull in the latest kernel/drivers/packages if you want thr most optimises experience though.
It is a unmodified Arch install that has a prepackaged setup, so you get a running desktop very easily and get the full.power and configurability of Arch
It's in a very good state, even with the bug you describe which is very low priority and I haven't even noticed myself, the majority of people play online.
They have made a game that is objectively better than D4 in some areas, I think that's pretty good for a small studio and saying they are incompetent and thoughtless just sounds like back seat driving to me.
In my experience the AUR is useful but almost unnecessary, and if you want to use flatpak you can get away from using the AUR entirely