I like little consoles like this but I never get one because I'm almost certain it would be novel and almost nobody I know would end up having one, unfortunately.
Update: and, importantly for the Steam Deck, you have a wide player base out of the box. Maybe not as much for the Deck itself (yet) but definitely on all three PC platforms.
The novelty is why they exist.
It would be neat if it was easier to broadcast the experience of playing the game to more folks like how playing back a song recorded from a groovebox doesn't require much more than a device with speakers than can play an audio file.
It is indeed quite limited, but I like terminal environments and (again) grew up with very constrained menu-driven software, so this is less of an toy than a very customizable tool; I'm not really interested in the game console emulation. One that can fit in a cargo pocket and is surprisingly affordable. The lack of a touchscreen or camera are pluses for me.
Not trying to yuck in anyone's yum, just point out that yes this is great and so is the deck...
The nice thing about the Steam Deck though is that you can carry around your development environment on the same machine. You still have to cross-compile to reach the 3DS and such.
I'm tinkering with 3D-printed slide-out landscape keyboards, but there are a lot of commercially available bluetoth keyboard cases.
1. The 2014 Nexus 7 packs a FHD screen compare to the 720 in TFA. Its display is shockingly crisp for an 8-year-old device
1. Enable ADB on device
2. Unlock the bootloader
3. Use fastboot to install TWRP
4. Boot into recovery and use TWRP to complete installation from zip files (Android ROM, Google apps)