Wine existed before Proton, Valve made it better but the project doesn't rely on Valve. Currently Linux is the best gaming experience. Zero bloat or nagware, everything just works. It's just ironic Wine/Proton ended up being the best platform for gaming on Linux. I don't think anyone expected it to run so well with virtually no performance impact.

Now with the Fex project, it might end up that running Windows games on linux on a modern ARM processor could be the best way to game going forward, especially for mobile platforms like the SteamDeck.