Lemmy could do with some form of user data download option so you can at least get a list of the communities you've subscribed to and the posts you've written and saved

That is something that is planned, just not being worked on currently. This thing was barely usable when the reddit thing happened, the platform was far from ready for the influx of users it received.

User migration could be made easier. At least being able to upload a list of communities to subscribe to.

That is also something that is planned, but not currently being worked on. Like migrating your whole profile, including posts, to another instance.

That being said, there is a tool that will export almost all (as far as I can tell, the profile pic is the only thing it doesn't export) of your settings and communities from your profile in a file and then you can import them on another account.

[email protected]

And the big one ... the fediverse doesn't enable you to own your data and profile in anyway unless you self host ... at some point down the road, it would be good if this could be addressed.

Also on the backburner. It's planned, just currently not a priority.