Why didn't everyone abandon Twitter for Mastodon when Elon bought it? Why didn't they even abandon it for Blue Sky until years later? Why is Twitter still as busy as it was when Elon took it over?

Because it requires a new account. Migrating PDS on bluesky does not require a new account, is invisible/transparent to your followers and following, and the end goal is that migration will be easy enough that you can do it in less than 5 minutes with no technical skill.

Bluesky/atproto is still very early/very young but the general theme is to focus on the UX and ergonomics to make decentralisation viable without forcing the user to be technical enough to care about it.

i.e. The end goal is that people should be able to say "fuck bluesky", click a button, wait for a loading bar to finish, and continue using bluesky without using bluesky PBLLC stuff.

To be clear we are not at this point yet and bluesky PBLLC is not suddenly hostile yet either. Triage is in order of priorities so some more important UX aspects are being handled first.

My personal prediction is that this should be a solved problem within less than a year but of course we'll see.

Migrating PDS on Bluesky requires a new account if your old PDS doesn't want you to migrate, or if you get banned from the PLC directory.

This isn't strictly true. If you can sign a did document (i.e. you've set up a recovery key), even if your old PDS refuses to cooperate (or disappears entirely) you can still move to a new PDS and deactivate your account on the old PDS (as this is done via your did document)[1]. It's not exactly trivial to do currently but tools are being developed that automate the process and render all this down into easy to use apps.

> or if you get banned from the PLC directory

This is technically true (for did:plc users) but this isn't a thing that's happened in the past and in the event it happens in the future (or even is seriously discussed in the future), did:plc will be in a substantially different situation than it is currently and the community should be situated by then to handle a federated or coordinated PLC directory.

1. https://www.da.vidbuchanan.co.uk/blog/adversarial-pds-migrat...