I didn't read that comment as saying that they "secretly control the world," but rather that the combination of changes in communication technology and those mental disorders leads those people to have a wildly disproportionate voice and impact.

I mean: elections are often won or lost based on which candidate can run the most ads. It's not too hard to believe that a disorders associated with excessive internet use would have an undue impact on society right now, due to something like having disproportionate share of social media posts.