I just spent last night migrating off goodreads and moving my lists out of libby, and there are definitely still some rough edges, but it'll get you there.
Bookwyrm is open-source, works similarly to Lemmy (i.e. is a federated platform). Storygraph and LibraryThing are also popular alternatives, but IIRC they're both closed source.
Personally I think just creating a spreadsheet file with your reading data is better. (In LibreOffice, of course.)
If you want a social platform then Bookwyrm is the way to go. If you just want to track your books and ratings you may enjoy OpenLibrary, that website also allows you to legally borrow books and read them for free which is really cool.
Try the literature board on 4chan especially some of the resources in the pinned posts at the top for some good recommendations. Not exactly like Goodreads but some good reading ideas from the community.