alt Hacker NewsHighly depends on what you're streaming. If you stream arcade 2D games of the past, or software development, it should be perfectly fine.
AAA titles with newer graphics, well, you can always send a capture the PC with the nvidia card's screen through a capture card.
Back in my days of streaming, macOS was no option, cca. 2017. Today I'd do it with any M processor mac without a second thought.
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.