>To solve this, they should close sign ups. Why haven't they done that yet?

They do periodically closes signups.

>I would like to think this is true, but there are just too many frustration stories of confusion of 'which instance' to choose, losing posts due to admins (and followers) shutting down instances and having to tell your followers where to go next.

Except on bluesky, you don't even get to be confused because it doesn't support any kinds of moves!

It's pretty simple really, Bluesky hasn't magically figured out how to make proper federation work. they just say they're federated but in reality they're really just centralized.

> Except on bluesky, you don't even get to be confused because it doesn't support any kinds of moves!

This is simply not true. There's hundreds of folks who have moved their stuff over. I haven't yet but will be doing so, been too busy with other stuff. But I follow a bunch of people that have moved, and there was zero disruption on my end.

The issues you describe are integral parts of decentralized protocols, and they can't be solved by technology. The reason Bluesky does not have these problems is because they are de facto centralized. No confusion of choosing servers if there's only one server, right?

> having to tell your followers where to go next.

On Mastodon, you can set up an automatic forwarding so your followers automatically follow your new account, they don't even notice you have switched instances if they don't look closely at your handle.

Mastodon migration is not atomic and requires the instance you are migrating from to remain operational (and non-adversarial) long enough for all of your friends' instances to notice you have moved and update their contacts. It doesn't preserve your follows. On Bluesky you just need to push your repo onto a new PDS and sign a new DID telling the network which PDS has your data. Everything else is seamless and atomic.

I personally find Mastodon confusing and I'm always unsure if I'm on the "correct" instance or not. I understand that all the instances can talk to each other, but it still feels disjointed to me; like I'm missing part of the conversation because it's happening in the other room.

Bluesky doesn't have the same problem. I understand that they don't have true federation today but that's not really a blocker for me. I'm don't want to limit my reach just because something isn't perfect right now. If they get true federation working in the future, great! If they don't then I'll just deal with moving to the next platform. Granted, I don't make money or anything from any social platforms, but it's not the end of the world if you have to start over. At least not for me.