So if we had 100 Mastodon instances, and each instance had 100 users, we have a healthy Fediverse of 10,000 users.
Now 1 of those 100 instances decides to do something. Maybe they make a moderation decision and become super pro Nazi. Maybe they add a new feature where you can video chat with other users.
Now Nazis are frowned upon. So if 1 instance of 100 users is full of Nazis, the other 99 defederate from the 1. The Fediverse now has 99 instances of 100 users and we have a healthy Fediverse of 9,900 users.
But maybe video chatting is a neat feature. Initially only 100 users can video chat with each other. Other instances add video chatting, but not in a compatible way. Some users can video chat with each other, some can’t, & some don’t like the feature at all. As a community the different instances and developers work together to figure out what should happen to varying degrees of success.
But let’s change things. 1 instance has 7,000 users, a second instance has 2,000 users, and a few dozen instances have a few users, we still get a healthy Fediverse of 10,000 users.
But maybe the 7,000 user instance becomes pro Nazi. The smaller instance can defederate, but now you have the 7,000 user Pro Nazi Fediverse, and the 3,000 user Anti Nazi Fediverse. It isn’t broken. The smaller Fediverse still exists, but it’s smaller. Maybe the 2,000 user instance would rather rejoin the larger Fediverse. Maybe Nazis aren’t that bad. Now we have a big Fediverse of 7,000 Nazis and 2,000 Nazi tolerators. The 1,000 user Fediverse still exists, but is MUCH smaller. Not great, for either Fediverse.
Or what about the video chat? What if the 7,000 user instance adds video chat? What if they don’t want to share how it works? If you want video chat you have to move instances. Now our 7,000 user instance has 8,000 users. Now our 8,000 user instance adds ads. You can’t leave if you want video chat.
The Fediverse can’t be destroyed, but it can be shrunk. If it shrinks too much too fast, it might cease to be useful. If it grows too much too fast, it might cease to be useful.