I think the Deck's capability to be relevant for years into the future depends entirely on whether PC game developers target it as a platform. Many of the top best selling video games from the past few years struggle on the deck even on low settings (Baldur's Gate 3, Oblivion Remastered are a couple I've tried with rough results). Of course there's still a massive PC backlog and ample lower spec games released each year.
Is anyone here aware of whether developers are using the Deck as a minimum spec and thus their technical constraints?