just throwing out there that ActivityPub has been given Recommendation status at the W3C (what is a recommendation? https://www.w3.org/standards/)
ATProto is a NIH reinvention of the wheel by a "public benefit LLC" of unclear ownership* that has demonstrated time and again its unwillingness to take a seat at the table within a group like the W3C or the IETF in protocol development.
What is ActivityPub, you may ask? https://en.wikipedia.org/wiki/ActivityPub
* EDIT: I completely missed there was Bluesky $8M seed round in July, lol. It's now a public benefit C Corp whatever that means.
https://techcrunch.com/2023/07/05/bluesky-announces-its-8m-s...