I don't think that's a possibility. All of those platforms make profit by displaying advertisements to people. Thet means they have to bind the users to their website or app. To display ads there. That's why they commonly restrict things and don't interconnect, but keep the users in a walled environment. I don't see any way for that to change with the current business model of all of the social media and big tech companies.

I also like the Fediverse. And I'd think it'd be awesome to have that. But I think it's a very unrealistic idea. Except for maybe if the EU forces them to open up or something like that.