> AFAICT, the Linux side is making progress, but still more games can be run from macOS.

I don't believe that's true. According to ProtonDB, 80% of the top-1000 most-played games on Steam are confirmed working on Linux: https://www.protondb.com/dashboard

I haven't seen any source documenting nearly similar success rates with Mac but I also haven't seriously tried gaming on Apple Silicon.