Despite understandable misgivings with ATProto due to its corporate origins and its architecture lending itself to centralization, it’s still open source. Moreover, it serves a different purpose compared to ActivityPub, in that it specifically aims to enable and support larger scale social networks.
In a way, ATProto could be complementary to ActivityPub, but for this to be the case, there needs to be more shared understanding between both communities. People working on both recognize the faults in existing social media, and aim to address them in different ways.
ATProto provides an opportunity to break down big social media enclosures with data portability and a similar vibe to big social media, but with more individual empowerment to adjust what they see. The latter point is a commonality with ActivityPub, but ActivityPub provides a different angle of breaking the big social media enclosures.
Where ATProto serves the interests of those into big social media vibes, ActivityPub serves the interests of those into small social media vibes. In other words, ATProto scales up, where ActivityPub scales down.
ActivityPub is arguably a better protocol for both individual and “small” group empowerment, as it can enable otherwise less active, small platforms to connect and ensure there’s always some level of activity to encourage people to come back. Think of old forums that, on their own, gradually faded out as people stopped visiting and posting for more active online communities. ActivityPub can serve as a buffer against that, to some degree.
Together, both protocols could provide a better, open social web, and perhaps effectively topple big social media enclosures. After all, who wouldn’t like to see the web without Meta/Facebook and Twitter/X?
TL;DR: ATProto/ActivityPub have a common foe in big social media enclosures like Meta/Facebook and Twitter/X and would be better served working together to erode their influence.
This really shouldn’t be a consideration. ActivityPub is a public standard for this kind of communication between websites, and the protocol really needs to be agnostic about which websites one is interested in using it to connect with. “I don’t want Amazon using HTTP along side my indie blog” is a nonsensical statement, and so it “I don’t want Facebook using ActivityPub”.
I agree and I personally think the whole preemptive Threads ban is stupid in general, but at least one major bridge has had to be turned off because people on the Mastodon/ActivityPub side of things got angry. I don’t mean the people behind ActivityPub of course, I’m sure they were chuffed their protocol got buy-in from a major player.
If anything, large corporations using open standards is better, even in situations like Google Talk where Facebook and Google dominated the protocol for a while; at least the protocol is useful for regular people.