Throughout my life I have spend a lot more time on handhelds than I have on home consoles. So I'm very much more inclined to play on a handheld console. Ironically, I don't count the Switch as a handheld. I've been using it as a home console exclusively and I think what trips me up about it is the size? Compared to a GBA or 3DS it's just so much bigger. I consider the Switch Lite a handheld, though. But I don't own one.
Handhelds because it's easier to multi task while you play those vs a console. Also, if your TV is mounted high on the wall like mine, you have to look up while you play on a console and your neck/back get strained. While playing on the almighty 3DS or Switch Lite, you can lay on your bed and sprawl out your body in comfortable fashion while you play, a luxury you don't have playing on a console
tbh, i'm kinda split between both? i like both equally, although admittedly going back to my 3DS after playing my Switch a lot is rather... trippy because of the screen. u_u so i don't feel very motivated to play many (3)DS games, anymore.