@evan An added dimension is that there are some fediverse implementations that are indeed server monoliths, even though most are not.
In a pitch presentation I've previously given, I tried to visualize the differences to closed social networks like this. A dot is supposed to represent one person, and Mastodon is more of a nebula than a single unit.
I'd be open to suggestions for improvement. 🙂
Edit: The next post in your thread has the improvement ideas. 😄 I'll take that on board, thanks!