I actually used an M1 MacBook Air for encoding/compositing by sending the video/audio sources over from my main PC with DistroAV (LAN).

Worked reasonably well (you can send camera/VTuber output and captured video from game and any overlays separately, or just use the setup in a similar way to a capture card and run ONLY the game on the gaming PC and everything else on the Mac), but added some complexity to it all.

A beefy Nvidia GPU would make that setup not necessary, unless you want to directly play games on the Mac.