I have been skirting around the edges of BlueSky trying to crystallize my thoughts and why I won’t be signing up. Along comes Christine Lemmer-Webber @cwebber@social.coop and writes a really in depth post that does that and so much more. I’ve provided some call outs that really reinforce my thinking, but I highly recommend you go read the original in full. (it is a long, and technically concept heavy, read but worth the effort if you are interested in how this stuff works.)

How decentralized is Bluesky really?

“Message passing” vs “shared heap” architectures:

If this sounds infeasible to do in our metaphorical domestic environment, that’s because it is. A world of full self-hosting is not possible with Bluesky. In fact, it is worse than the storage requirements, because the message delivery requirements become quadratic at the scale of full decentralization: to send a message to one user is to send a message to all. Rather than writing one letter, a copy of that letter must be made and delivered to every person on earth.

Direct messages are completely centralized:

The answer, if you guessed it, is centralization. All direct messages, no matter what your Personal Data Store is, no matter what your relay is, go through Bluesky, the company.

Bluesky is centralized, but “credible exit” is a worthy pursuit:

Even though the majority of Bluesky services are currently operated by a single company, we nevertheless consider the system to be decentralized because it provides credible exit: if Bluesky Social PBC goes out of business or loses users’ trust, other providers can step in to provide an equivalent service using the same dataset and the same protocols. – Bluesky and the AT Protocol: Usable Decentralized Social Media