The reality is that the number of games, even AAA ones, that are releasing at that high a "minimum" performance requirement is incredibly small compared to other games that do release with more modest system requirements. Games that are "just good enough" graphically to go along with their gameplay tend to be the norm, I think, with the few games that really go for pushing visual fidelity being respectable in their own right but not frequent enough to fret about. What will matter the most is what games you want to play and what their requirements are, and that's basically impossible to project out 1, 3, 5 years out or however long you expect the hardware to last.
For what it's worth, I have a Steam Deck and spend a lot of time playing on it, but pretty much every "AAA, big budget => big graphics" game I want to play I'd exclusively do so on my gaming desktop (or remote play on Deck if I want to play it there at all), while sticking to 2D and lighter 3D games on the portable device directly. This is mostly due to what kinds of games I enjoy playing on what form factor, as for example my decision on what to play docked vs portable on the Switch is much the same way, and for about a year after buying the Deck, my desktop hardware was so out of date it was getting generally worse performance than the Deck yet I'd still use the desktop for "spectacle" games, but the necessary graphical quality to go along with that tends to correlate well.