Every year or two someone "unmasks" Banksy and they name the same guy and then everyone collectively shrugs.
Everyone knows. It's some bloke. Not some supernaturnal painter-geist. Just some bloke.
Just like Daft Punk was two French musicians of some sort, that have names that most people don't care to know.
The anonymity was never really as interesting as the spontaneity. So what is the payoff here?