You can do some really cool stuff with emulation. I’m playing Fire Emblem Echoes Shadows of Valentia (3DS) emulated at 4x native resolution with a HD texture pack at the moment, and it makes that game really enjoyable. 3DS games in general benefit a lot from increased resolution you can do while emulating.
Plus these things like widescreen on games that didn’t have it, cheat codes, 60fps patches, fan translations, increased resolution, mods (Luminescent Platinum is so cool). It’s just such a neat world on top of just playing older games that you can’t purchase legally or conveniently anymore.