I think it’s somewhat of a false premise … the attraction of the fediverse is that at a large scale it would be hard to predict. It’s more dynamic and flexible to where people are actually up to with things. So the promise of the fediverse at least of such a future would be many things constantly changing without as much inertia built into the system.
Beyond that, if it were truly successful, I think, or would hope, that it would bring about a true democratisation of the internet, where people could truly feel like they personally own a part of it and contribute to other parts as a collective.