It's a no-brainer for me. The headache of setting up emulation of consoles more modern than about N64 era makes it way less appealing right from the start, plus the Switch is way lighter, and all the native hardware features just work better when you aren't going through a few levels of translation (Steam's controller mapping is great, but gyro working seamlessly is hard to beat, and amiibo support is a hassle to replicate). The Switch is a bit less comfortable to hold on its own, but there are lots of grips that fix that problem (I'm a fan of the Skull & Co one).
I've found emudeck on the Steam Deck to be surprisingly easy (I have a low tolerance for that sort of tinkering in my spare time). Downloading the right ROMs has been a little more painful (and slow), but once you've got them it's generally been just SCPing them onto the deck and then pressing the button to generate the menu entries.
Admittedly though, I don't care about amiibos or motion controls (I always turn them off when using my Switch).
