That does seem odd. It doesn't have to be a "console" distro like ChimeraOS, but maybe an Arch derivative like Manjaro would have been more appropriate. (I don't know many gaming-focused distros tbh)
If it's affordable for you, I would say take a look at the NUC Extreme kits for a living-room PC upgrade. Custom small form-factor that was designed for standard GPU sizes (check the dimensions carefully - my Sapphire 6700XT fit the specs but was still a tight fit), and it's fairly quiet even with graphics settings set up to high.
My wife has been happily playing her games in the living room this past week, and I've been able to sneak a few hours in between.
I'm gaming on a NUC 11 Extreme kit with a Sapphire Pulse Radeon 6700 XT running ChimeraOS.
Currently it is doing really well, though some games appear to not be using anti-aliasing and I'm not sure why. But aside from that I am super impressed with how well Proton and Lutris have come along!
I guess it depends on what your use case might be. I have heard that Manjaro is decent for a desktop Arch experience, but I have yet to try it.
My use case recently was for a living-room PC that works like a console version of the Steam Deck. For that purpose, ChimeraOS works really well. It's an Arch-based distro that uses the Steam Deck controller-first interface and so far is handling almost everything I've thrown at it. It even has a remote admin app where you can install games from GOG or Epic (although GOG support only installs the base game at the moment, no DLC or updates) or upload console ROMs for emulation.
I would say if you go this route, get a PS4/PS5 controller. The touch space is recognized as a mouse, which removes the need to attach a mouse for those moments when you need to get into the desktop (such as formatting a secondary drive for use in Steam).