> Except XMPP uses DNS for message routing from a human readable handle, user@host.com, but Matrix uses a central database "identity server" operated by Matrix.

> Except XMPP uses DNS for message routing from a human readable handle, user@host.com, but Matrix uses a central database "identity server" operated by Matrix.org and federation fails if this service goes down. Uh, no? Federation certainly does not fail if the identity server goes down. You won't be able to invite someone to a room by email address or phone number if whatever identity server you're using goes down, but it's nowhere near the critical path for federation.