There's a Fediverse alternative to Amazon's Goodreads called BookWyrm, you can find out more about it at:
https://fedi.tips/bookwyrm-a-social-network-for-people-who-enjoy-reading
You can import your existing book data into BookWyrm from Goodreads, LibraryThing, StoryGraph, OpenLibrary or Calibre. There's a guide to how to do that here:
If you want to keep track of the project, you can follow BookWyrm's official account at:
Yes, the decentralisation is the main reason for it existing, it protects people in many different ways:
https://fedi.tips/why-is-the-fediverse-on-so-many-separate-servers/