In concrete terms if your app has functions that do very little work but run for hours or days at a time blocking on external resources, and it is acceptable to add 100+ms latency + a serialization boundary to every function call, it is acceptable to take on a bunch of other tooling complexity, and you are willing to sacrifice verifiability of the code, then it might be a fit. In those situations the structure of it (or DBOS or similar) can help standardize that part of your app. Unlike a regular state machine based approach it's easier to represent branching logic and so forth in imperative code. I think its popularity is like the Mongo NoSQL fad, it looks convenient up front but in practice is very painful in most situations. Having used it a fair amount I would recommend starting with actors and state machines, especially in this age of robot code where it's easier to apply heavier approaches to testing in verification.