I've been trying to figure this out too. My insights actually started from a post made here, where someone talked about post 'weirdness'. There are so many pos

I've been trying to figure this out too. My insights actually started from a post made here, where someone talked about post 'weirdness'. There are so many posts that we skim all of the time. If there is a post that is weird, we skip it. If there is a thread that is weird, we collapse it. What I realized however, if that weirdness is coming from the people who are here all the time, at the top of the karma charts, and people see their name all of the time and respect their opinions, that you can become more weird. And so as the community grows and as you communicate with more people, as you see the same person less and less often, the ability to be weird drops. The larger a community, the less it can move as a cohesive unit, the less it can find new ideas. So what we're really looking at is how Metcalfe's law clashes with the Overton window. That's why Dunbar's number is a thing. As we communicate we subtly change our opinions, and when a group becomes to large, the communication scaling at a factorial rate eventually meets its limit. You end up with a group that believes different ideas, and therefore the best thing to do is split. We don't see the splits in existing social media because even though the Overton Window is smaller and smaller with larger and larger numbers, more and more people are being pulled into it, and exponentially more people are tossed aside.