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.

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

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".