> Especially binaries and/or Steam games, things running through Wine can be a pain because standard libraries are in non-standard locations.

Steam just works, though? I've been running nixpkgs.steam for a while, and it has consistently been the best Steam-on-Linux experience I've had. Precisely because what Steam sees is tightly controlled, and there's no place for accidental DLL/.so hell, and ambient changes to your OS making it into Steam/games breaking its assumptions.

(and for everything else you have steam-run/buildFHSUserEnv)