They're barely any good to play turn-based games like Pokémon and Earthbound
Exactly what I do.
Emulators on phones themselves, I use them only for RPGs which are turn based.
I have all main Pokemn and Mother games in there.
Playing any FPS or precision-heavy platformer on a phone is just plain stupid and really uncomfortable.
Also, buying a controller for it is not appealing to me.
Unless I have a phone with a huge-ass screen and some octacore processor or some shit like that, it's uncomfortable.
To me, there's a certain beauty in having a proper console/handheld hacked with multiple emulators.
Do I have the itch to play on my TV?
Wii U got me there.
Do I go on vacations or have a long trip ahead?
N3DS (and Switch hopefully in the near future) have my back there as well.
Going for the phone alternative is cheap, yeah, but I find enjoyment and gain some knowledge about the console in the hacking progress. More so if I get to enjoy my entire Nintendo library of games in just one console itself.