@Gargron uhm... well... but it's not entirely like it solves everything. I still have
1x mastodon
1x bookwyrm
1x pixelfed

It solves to connect to all your friends on the fediverse, whatever they use but it still requires you to have lots and lots of accounts on the fediverse to make use of different things. So Friends and people have to follow at least all of my active accounts and I have to repost everything on all accounts. That's at least one downside.