Why bluesky and threads should embrace ActivityPub.
Social media is splintering - accelerated by the fall of Twitter. It's not 2010 and a social media network is never going to be what twitter was in 2010. They'll might as well develop social media that can talk to other networks
Their protocol (called the "Authenticated Transfer Protocol" or "AT Protocol" for short) fixes some issues that ActivityPub has.
For example, you can use your own domain name as your handle, even if you're not hosting the server yourself. This makes your username portable - you can move to a different server but keep the same username. You just need to update some DNS records. It's not possible to move server but keep the same username with ActivityPub, since your username is always at the server's domain name.
What I'm hoping is that the developers of ActivityPub take some ideas onboard, but it'll be hard given the current design of the protocol. Maybe we'll get a new version of ActivityPub one day.