The thing is, it is more complex than that. Reddit's authoritarianism is an important part of why some of those other social networks you listed became what the

The thing is, it is more complex than that. Reddit's authoritarianism is an important part of why some of those other social networks you listed became what they are in the first place and/or why they were created to begin with. The more censorship of political views that lean a certain way there are on big mainstream platforms like Reddit, the more likely it is that refugees from that censorship will move to other platforms, therefore leaning those platforms highly into the opposite ideological direction. That is even more true given that the people who care enough to want to move will tend to be the more ideologically extreme parts of the original network's user base. Also, 4chan does not suck. /pol/ sucks because it has been completely overrun by right-wing political extremists and literally mentally ill people, so it is an echo chamber just as much as Reddit is, just less censored. But many of the other boards have discussion from varying perspectives.