There's a lot to like in the overview statement from Twitter's "blue sky" decentralization project.
The problems they identify with ActivityPub are real and they indicate good understanding of the issues.
They mention blockchain only in passing, noting the fact their engineers have worked on it in the past, and don't seem to think that blockchain is needed or wanted in a communications protocol which doesn't have a double-spend problem nor need censor-proof transactions or global state.
They seem to want content-addressable data, user-creatable private-keys as identifiers, better portability than ActivityPub can offer and don't apparently have any bizarre plans for utility tokens.
So that's more optimistic than I'd have expected.
https://blueskyweb.xyz/blog/3-6-2022-a-self-authenticating-social-protocol