This is 100% the reason for the documentary in the first place. Quote from the director:

My dream would be that when people watch it, they take flat Eartherism as an analogy to something they believe in, because it's so easy to demonize another group or another person for something they think but you're kind of just as guilty if you do that.

These are humans, people that are missing something in their lives, and this community and their "secret knowledge" grants them that.

I see the SovCit movement as exactly the same thing, but when one digs deep enough, maybe one finds the same in the fanatical MAGA crowds, and in the most fervent religious people, and it's not a coincidence that there's an overlap in membership between these groups...