Very vague article. I would say that the #1 reason to split a monolith is if your engineering team has grown too big. The main advantage in my experience of “microservices” is that they allow groups of engineers to build & deploy with much less inter-group communication. It’s a great way to scale an organization.

There are other reasons to split a monolith of course, like in high-availability high-traffic services, where isolating specific call patterns on separate fleets makes the system behavior much easier to predict. But primarily I think microservices solve organizational problems.