1) no fussing about with stuff that most people can't or don't want to do, 2) nice controllers included, no config faffing about, 3) last I checked even the Rpi3 had noticeable slowdowns and/or frame drops on Starfox and Super Mario 2—it's getting close, though, so a hypothetical Rpi4 might get us to 100% acceptable SNES emulation.

Proper licensing and giving money to a company that makes good games.