My main take on microservices at this point is that you only want microservices to isolate failure modes and for independent scaling. Most IO bound logic can live in a single monolith.
It is simpler than that. You only want microservices in the same cases you want services (i.e. SaaS). Meaning, when your team benefits from an independent third-party building and maintaining it. The addition of "micro" to "service" indicates that you are reaching out to a third-party that is paid by the same company instead of paying a separate company.
It would make more sense to say that the event tree should not have any cycles, but anyway this seems like a silly point to make.