Comment by spankalee

atproto apparently has some real advantages over ActivityPub in terms of data portability. Similar to Bluesky vs Mastodon, with Mastodon you're fairly strongly coupled to your server, you' can't just move your data and retain all your connections. atproto makes that possible, and that could be really important if you want to say move from a shared forge to a self-hosted one or vice versa.

atproto apps also tend to separate the PDS form the app view, so you can easily use the same data with different front ends.

And, atproto's identity model is much better. Rather than being tied to a server like the data, it's DID-based and you can use it with multiple PDSes.