Back in the 90s, when mcdonalds.com was owned by some yokel who thought to register it before anyone else, I used to say that they couldn't do capitalism on the internet, and look, they pulled it off! We only had to throw every shred of social cohesion out to make it happen, but hey, the attention economy is in full swing!
Rubbish, lad. These platforms manage accounts in their millions within the garden every day, and you're telling me that they can't manage to open up a hole in the API to let someone add and read posts that way, rather than through their sadistic web interfaces? After everything they've already done?
More to the point, ActivityPub is just the current popular prototype, the Bitcoin if you will, of the federated social space. We'll get it sorted just fine.