Proton and Steam Deck seem quite remarkable. So yes, Steam products run well on Steam hardware... however I install a lot of WINE games and I am not seeing that Steam give back to the broader WINE community and open source project. If Steam could somehow propogate all that Linux knowledge back to the project it would be a real win for Linux gaming and a big pat on the back for them then.
what are you talking about? Valve has advanced wine lightyears since jumping into linux with the steam machines years ago, and their wine patches have lead to countless forks that people use for better compatibility. Wine was terrible before valve stepped into the linux space