There is no global coordinator "service" in FaunaDB either. The "coordinator" is a stateless function on available on every node. The log is a stateful, logical function implemented in Raft, so no different than a Paxos ring in terms of failure modes and high availability.
Think of it as a way to scale a single Spanner tablet to support the entire dataset and eliminate the 2-phase commit, as well as the associated write skew or clock ambiguity window.
Paxos/raft is an agreement service where nodes agree on entries in a single log. I have no problem calling it a distributed/global coordination service for agreeing on entries in a log.
Think of it as a way to scale a single Spanner tablet to support the entire dataset and eliminate the 2-phase commit, as well as the associated write skew or clock ambiguity window.