@WeirdWriter On Fedi, many platforms offer an export of your posts and media in folders and JSON/XML files, zipped up. You can recreate all of your posts with these.

Bluesky gives you a single CAR binary file, with no media. It is not human readable. And you'd have to request your media separately.

I assume there's some opensource tools to create bluesky exports in mastodon format, or at least a readable one? Maybe? A quick search show promise.

https://romiojoseph.github.io/bluesky/bluesky-repo-explorer/