I haven't done much PC gaming lately, but I ran NixOS on the living room gaming and emulation PC for years, and it likewise worked well for me.

It's probably not a use case people think of when they think of NixOS, but it's popular with users and contributors nonetheless, and thus also fairly well-supported.

It's also generally a nice way to cope with proprietary NVIDIA drivers (although the new open-source ones are already available in Nixpkgs as well!).