Bluesky lacks the one federated feature that is absolutely necessary for me to trust it: the ability to leave Bluesky and go to another host and continue to talk to the people I’ve entered into community with there. While there are many independently maintained servers that provide services to Bluesky and its users, there is only one Bluesky server. A federation of multiple servers, each a peer to the other, has been on Bluesky’s roadmap for as long as I’ve been following it, but they haven’t (yet) delivered it.
By definition, a federated service is one the is part of network of independent services that interact for a greater good. Call your proprietary network protocol “open” and “decentralised” all day long, but if you allow only one instance to use the protocol you have a closed system. Mastodon is federated, Bluesky is not.
I doubt Bluesky will ever be federated. The AT protocol was never more than a marketing gimmick to fit the Zeitgeist during Twitter’s meltdown; to position Bluesky as a viable alternative. Bluesky is on a Twitter’s beaten path. The “open” protocol will be locked down as soon as the service attracted a critical mass of users big enough for VCs to monetise. Bluesky will end up as a walled garden, like Facebook, or Twitter.