Are you looking for Crossover? It's a bit annoying to not run Steam natively (no cmd+H to hide, etc) but it's got a lot of support. Performance is decent on my M2 mini, and even cross-platform stuff like Baldurs Gate 3 is comparable performance to native.
Especially anything that Mac Steam natively calls out lack of 32bit support has good support.
Sadly, that's not true—for instance, I was trying to run the Shadowrun Returns series the other day, and while it launches, it will hang indefinitely when you try to actually start a game. (M4 Max)
I previously played through Returns, Dragonfall, and part of Hong Kong on Mac before the 32bit-apocalypse.
CodeWeavers, the developers of Crossover, also do most of the development on proton under contract for Valve.
This is speculation but I suspect there's something in that contract that prevents Valve from competing with Crossover on MacOS.