Using a handheld PC is a whole lot better than using a Switch - better performance, wider selection, cheaper games.
Whether you opt for a Steam Deck though is pretty dependent on what kind of user you are (and I say that as a Steam Deck owner twice over, I got the LCD and upgraded to the OLED).
If "it just works" is a key selling point to you on the NSW, and you hate fiddling around with stuff in general, I'd recommend picking up the ROG Ally instead. You see a game on Steam, you buy it, it'll work. There's no "this game doesnt work because its got EAC", or "this game doesnt work because the Japanese folks who developed it were part moon octopus" - my cousin, who is a more casual gamer, shifted from a Deck to an Ally and was exponentially happier with his experience.
Considering the price and its compatibility, the Steam Deck remains the better value. But I'm happy with it given the context that its a complementary gaming device for me - if shit doesn't work, no big, I'll just play it on my desktop or my laptop. But having a Steam Deck as my sole PC gaming terminal would drive me insane, lol.