This explains it best:

> When Facebook was born, it gave people who were already using MySpace a tool that would pretend to be you and log into MySpace, collect all the messages that your friends had left for you, and put them in your Facebook inbox. You could reply to them there, and it would send them back to your MySpace outbox, so your friends would see them. And that was what allowed Facebook to take so many users from MySpace so quickly. This is what interoperability is about. But if you tried to do that today, Facebook would use laws that were either enforced differently or did not even exist at the time of MySpace, to ruin you.

> If we were to restore this “noble ancient art” of technological interoperability, the users who are so obviously discontent with the platforms they use would consider the costs low enough to leave and join better spaces. In turn, the companies would be smaller, would pay more attention to user satisfaction, and could not push around the governments that tried to hold them to account.

https://www.greeneuropeanjournal.eu/cory-doctorow-how-to-tak...