Steam is very upfront when you’re buying a windows game on mac. There’s a big banner saying it’s not for your OS and likely won’t work. There’s a compatibility icon for mac, and it’s filterable, for library and store, so you can get mac games. There’s an additional click-through screen on the store page with a checkbox. There’s a lot that’s filtered out!

The proton story pretends like you can run every windows game on steamos, verified or not. It’s quite different and tbh a little dishonest. I wonder how much of it is avoidance of alert fatigue (because many many unverified games do work) and how much if it is trying to sell users on steamos.