Gaming laptops are really just portable PCs. If you’re playing on them on in the usual “Keyboard and Mouse” way then you need to put it on a table to make that work properly. Maybe you could do it on a sofa but it’s very quickly going to get uncomfortable.
Handhelds on the other hand are extremely portable and happily usable anywhere. They’re also a lot cheaper than a gaming PC! I’m a big fan of my Steam Deck and recommend it a lot, but I should admit I also have a Gaming PC which I use for multiplayer stuff with my friends