"Only viable instance" is not really the correct framing - Bluesky doesn't have instances. Anyone using ATProto without Bluesky will still be "on Bluesky".

When you go to bsky.app, you're interacting with the Bluesky AppView; one key feature of ATProto is that any AppView can interact with any (consenting) Personal Data Server (PDS). So you can self-host your PDS but still use bsky.app if you so choose. But critically, anyone can write an AppView; there are reimplementations of Bluesky as well as other social apps that use the same ATProto infrastructure. That would be closest thing to a Mastodon instance, except you don't have to host your data on it in order to use it. Imagine being able to go to a Lemmy instance and just post things with your Mastodon identity, and have everything show up without Mastodon having to know anything about Lemmy magazines or its special upvote / comment formats.

The actual centralization in ATProto lies in a combination of unfortunate design decisions and genuine friction in the self-hosted path. Being totally reliant on Bluesky is the happy path, self-hosting your PDS data is difficult but doable, and being totally independent of Bluesky is only possible if you do everything correctly right at the start.

First off, Bluesky doesn't offer any GUI tools for PDS migration. If you want to get off their PDS, you'll need to bust out command-line tools and possibly do some steps in advance of when you need to migrate in order for everything to work properly.

Second, even if you're on a PDS, you're still reliant on the Public Ledger of Credentials (PLC) to host your Distributed ID (DID) document. The PLC is run by Bluesky, although they've taken steps to make it easy to notice if they were to do something fucky with the PLC. But let's say we don't like that. There is a solution: you can host your DID document on a normal web server. Problem solved?

Well, if you were setting up an account for the first time, then yes, the problem is actually solved, you're 100% independent of Bluesky. But if you made the mistake of registering an account normally, you have a did:plc identity. And one core principle of ATProto is that identity names never ever ever change. So if you go and make a did:web identity, it's like having a second account, there is no way to tie your old did:plc identity into it. In fact, I'm pretty sure you can't even redirect one did:web identity to another (say if you need to switch domain names)

Regarding Bluesky's "independent protocol governance organization", they made the same promise about the PLC; but it hasn't actually been transferred yet. I would be a lot more bullish on ATProto if there was a way to migrate DIDs and retain all your followers and shit. And if there was proper graphical tools for data migration.

Bluesky has a data store, handles account authorization, and runs a web app that provides a UI to access the backend services. That's an instance, whether they call it one or not. Refusal to admit this is obfuscation for reasons I cannot understand.

The nightmare of the Wsocial rollout is a testament of the massive control Bluesky has on the ATProto network.

If Wsocial was on ActivityPub or Nostr nothing similar would have happened.

ATProto has serious centralisation problems, baked into the design. And it makes sense, considering it came out of a Twitter R&D experiment to "decentralise" Twitter itself. Pure federation was never part of the initial design.

ActivityPub and Nostr solve the issue already.

> I would be a lot more bullish on ATProto if there was a way to migrate DIDs and retain all your followers and shit. And if there was proper graphical tools for data migration.

This is exactly where I’ve landed re: ATProto. If you actually want to self-host everything you lose one of the biggest draws of it, the migratable IDs.

I was looking into it to build an alternative to Threads/IG/TikTok for one of my hobby communities that’s become almost entirely reliant on Meta/Tencent. Being able to plug into the wider AT Proto world was a big draw, but not being able to self host a true alternative to did:plc has put a halt to that for now while I figure out what I want to do.

Thanks for your clear and concise explanation!