Yes and no - the work that's gone into it, and into Proton in general has made game support on linux generally leap forward. I don't have a Steam Deck myself, but because it exists, things are getting patched in Proton often before games even come out, which is a far cry from where things used to be with Wine.

Having a site like ProtonDB to be a single place to go look up any tweaks or config flags for Wine/Proton to get a game to work is invaluable, and it's now actually getting good traffic and data because of Steam Deck.

Presumably you mean that as a criticism but "being supported by a multibillion company" is normally a fantastic sign of success, and "a single hardware configuration" is an indicator of seriousness about guaranteeing a good UX.

Look no further than power management/sleep/awake, which is flawless and snappy on steamdeck. That's more than you can say for 95% of "supported linux laptops".

Valve's work on Proton has been repurposed for other hardware configurations with great success