>either because the Linux version was outdated, unmaintained and buggy, or it simply performed better.

Sure, I can see that. My solution to that one day will hopefully be to make sure devs can keep their linux platforms updated, not give up and go around it with a windows build.

But Proton discourages that, not encourages. As you said, Steam doesn't want you to know what build you are playing, and if the audience doesn't know, then the devs won't care either.