It's an interesting concept and while I used to do that about six years ago nowadays I prefer standalone emulators for features and performance.
But it can be useful in the rare case when your device doesn't support downloading emulators.
My 2 cents lol
"Oh so you're a dumpbro, right? Then prove your legally owned copy of Mother 3"
What do you guy's think about the ability to finally play more consoles on an browser I just noticed this feature on the snes and GBA vault.