the first *good* emulator for iOS is here
https://apps.apple.com/us/app/delta-game-emulator/id1048524688
the dev behind this has been working on it for literally a decade—if you remember the ancient GBA4iOS from 2014 that could be installed by setting your phone’s time backwards, he’s the guy who made that

only now it runs NES, SNES, N64, *and* NDS games in addition to Game Boy and Game Boy Advance games