transition actor use-cases (for smarties)

[boneskull]

From the docs:

Transition actors are actors whose logic is represented by a state-transition function, which is a function that returns the next state of an actor given:

• The current state of the actor
• The event that triggered the transition

This is very similar to a reducer function in libraries like Redux.

As someone who has never used Redux (or any other state-mgmt library--present company excluded), I don't understand the use case of a Transition actor.

• When should I use a transition actor?
• At first glance, it looks like that one could use a state machine in place of any given transition actor--but not vice-versa. Is this true?
• If that's true, then the limitations (including but not necessarily limited to those mentioned in this table) define the floor of reasons for avoiding a transition actor. Are there any other reasons besides those limitations to avoid transition actors? I hope this makes sense.

Thanks!