It's not hard to come off as more intelligent than you actually are. You just have to talk quickly and act like you know what you're saying. That can help you out for a little while, but the key to achieving genius status as an idiot is to get extremely popular. You have got to do Ben Shapiro's 2018 YouTube numbers if people will think for a second that you're not a complete fool.
A big chunk of the population believes that if you're successful, that must be because you're smart and talented, but that's just untrue. So many genuinely intelligent individuals will never achieve the level of notoriety of Elon Musk, but that doesn't make him intrinsically better than them. I sleep well at night knowing that even though Elon Musk has billions more than I do, I will always have a better understanding of memes than he does.