Personally I believe this all boils down to 'Platform Lock-in'.

I have to use Facebook because everybody I know uses Facebook. Just like when I was younger I preferred Playstation but had to buy an Xbox because all my friends had Xbox.

Nowa days we have CrossPlay across platforms.

If I could use a social media platform which has an approach to Privacy I prefer, while still being able to view my friends social integrations (who care less about Privacy but prefer more customised content) on another platform, that would solve these issues.

Legal agreements could prevent the processing of data by platform owners by other platforms or even some sort of E2EE with metadata tags.