Theres also 2 hour video essay analyzing Snape wives as a new religious movement that draws on the history of Christian mysticism, midrashs, and idea of what unifies religion as a concept. Why do you think Harry Potter fanfic has lead to so many movements like them and the Zizians?
Harry potter fanfiction itself didn't lead to anything. If Harry potter wasn't around, these groups would use some other popular media property. They wrapped these things in Harry Potter aesthetics because for nearly a decade it was one of the most popular pieces of media on earth. I also generally don't like to focus on whatever pop-culture thing is wrapped around these groups. It distracts from more meaningful discussion. It also leads to people comparing Snapewives and Zizians in ways that are not necessarily useful or material.
A lot of people cover groups like these from the angle of internet anthropology, or public interest journalism. This isn't inherently bad, people have done it well, but inarticulate discussion can lend itself to sneering internet freak-show behavior. Or more commonly, relegating the topic to an incurious fun fact.
