They are, that's true. I think there's three big differences, besides battery life. First is we already have small phones that can play simple games and provide entertainment, so we don't need an additional something like the Gameboy. Second is it's marketed towards adults mostly, which are going to have an easier time bringing it with them wherever they are, unlike kids who would have to take it to school or wherever. Third is the game selection is massive and uses your steam library, which you probably already have a lot of games for.

And that's a big reason I don't own a Steam Deck.

I would be much more likely to buy one of those tiny retro emulator handhelds. (I haven't done that either, but that's for an entirely different reason: decision fatigue.)