"Micro service" and "Monolith" don't have precise definitions anyway. Ideally, there's only one right architecture: the one that's sufficient for the problem at hand, all things considered (latency, availability, cost, provider, maintenance, conceptual integrity, ...).
I feel like the term "microservice" is open to misinterpretation (people tend to focus on the micro part a bit much; I remember someone waxing poetic about something like a csv parsing service they had). But surely monolith is quite unambiguous: a system which is deployed as a whole. That is, you cannot deploy some part of the system on its own. You want to get changes in part X to prod? Better be prepared to deploy A through W and Y and Z as well.
That feels fairly precise. But maybe some folks would disagree with this definition of a monolith.
