I mean, in an alternate universe where he got therapy, cut himself off from Mayhem, and made his own black metal band made of less toxic people, he probably also could've done well, and may even still be alive to this day. He's considered to be one of the best black metal vocalists ever, so that band might even have become the more memorable black metal bands. So yeah, it wasn't the stage part that was the problem, it was the untreated mental illness and the Mayhem (especially Euronymous) problem.