I've been working with akka for 7-8 months now daily. When I started, I would be working on applications and notice that actors would be used basically anywhere once inside the actor system for communicating between most objects. So I did the same - spin up another actor for x/y/z.
It seems to me that this may be too indiscriminate, adding complexity where it isn't needed - but I can't find any discussions on where actors vs plain synchronous or even async logic via futures should be used. I started pondering my stance after my coworker mentioned something similar. I realized several cases more recently where I have pondered a task and then avoided creating another actor because I could achieve the same result safely in an immutable implementation - eg something like getting configuration values from a db or file somewhere where you access very infrequently and will wait for the result is the actual use case.
In particular, it seems to me that any case where you're playing with immutable state, actors create complexity and limit throughput - a pure function in an object, for example, can be called concurrently with no risk with any level of concurrency, yet an actor can only process one message at a time. The alternate consideration is you'll park the thread if you need to wait for the result unless you start using futures but cases where you don't need to worry about async messaging or scale it seems it may be overkill to employ an actor.
So my question is - is there a bad time to use actors? I'm curious how erlang looks and would really like other people's insight. Or if there are some principles around actor use.