Social media has allowed all the individual village idiots to unify under one banner.

It used to be that every village had their idiot that everyone in the village knew to ignore. However, now the idiots can post publicly just like everyone else. So the idiots can now talk to each other. And as a group, they manage to achieve a perceived credibility by sheer number. So you end up with people that aren’t quite at that level that see the group and think they’re smarter than they are… and this just keeps growing at each level.

Eventually you have people with literal brain damage running major government departments.