I don't think you're quite following here.

EG have you ever heard about Power Ventures? That was a social media aggregator. You gave the website your credential for Facebook and others. It would fetch contact lists, messages, and so on, and present them in a single place. That gave you a kind of interoperability, or even a kind of federation. Obviously, Facebook didn't like that. This kind of thing just weakens their hold on users.

You'd think users here should like this sort of thing. But it's full here with people who passionately hate it, just as much as Facebook did. Facebook completely destroyed the company in court. The Fediverse is full of people who think that that's exactly right.