Devices like the GBA, the SNES etc. have specialized sprite and tile map co-processors that are an interesting challenge to use, especially due to the very limited CPU and memory. Effects like Mode 7 perspective requires you to catch a interrupt to change the affine transform of the tile map at every scanline. That's fun!
Many of the modern devices are just a fast CPU and an RGB framebuffer.
Personally, I feel I can make a nice of-the-era game on an old console like the gameboy and feel accomplished. Anything simplistic, or rather, games made with a low artistic skill (at least that I try to make) on newer hardware just feels cheap/tacky to me.
Not sure if I'm getting across what I mean, but having 8x8 sprites and limited colour palette means I don't have _as_ much to worry about, so trying to design a semi-alright looking player sprite doesn't take much effort (not that some people don't put in a lot of time and do incredible things with it)
Switch is much better of course, however only the old non-Mariko units can be jailbroken without modchips, and while I do like the hybrid design of Switch, I still think Switch as a handheld is bigger and heavier than I want for a portable console. This would be solved with Switch Lite, but all Switch Lites are Mariko.
I quite like my RG350 to play old games (playing Final Fantasy VI right now), so much that my Switch is on its case for quite some time.
Otherwise one is better off getting a used Android, a gamepad adapter, and just code away with the NDK/AGK.
Looks fun but it's not the only thing of its kind.