The only thing that is currently logically centralised is the pki server. And that is only to guarantee unique usernames during sign-up, and its data is mirrored on other nodes.
You can self host, and then your own node is responsible for storing your data (which could be a machine in your house, or eventually maybe even your phone).
You can self host, and then your own node is responsible for storing your data (which could be a machine in your house, or eventually maybe even your phone).