Maybe it is because I’ve used low end computers for most of my life but the Steam Deck definitely feels like it has several years of life left in it. I’m mostly filling mine up with PC and console games from the last 30 years but even Baldur’s Gate 3 works fine on it. There’s a huge library of games for the system, especially when you include emulators.
I’d much rather Valve continue working on Proton to get more Windows games running on the Deck and improving overall performance of the OS.