That's true, except for the fact that Matrix and XMPP are also distributed. What I really meant is that it uses a DHT for peer discovery and that the peers communicate directly, without using any central server. It is more distributed and more decentralized.

You are right, except:

- "Peer-to-peer" (Ring, Bleep/BittorentChat) and

- "Federated" (Email, Matrix, XMPP/Jabber)

...would be a better way to convey that distinction.

An image illustrating the different concepts: https://a.doko.moe/ubvuak.png