I think this is a piece of the pie. The thing to recognize that I think is just as important is that it is possible to state several common use cases (even synchronous microservices) as collections of append only immutable logs for system of record and an in-memory read/view state for readers and mutating functions.

I am using this pattern in risk, fraud and commerce and once new members in my teams get over the mental barrier of decoupling the append only log from state, it all just clicks for them.