Comment by randomswede

Yep, there's no real magic here. There's some understanding forced by a (successful) transition to microservices ,but a transition to microservices is not a requirement for said gained insight.

And if all parts of your system scale identically, it may be better to scale it by replicating monoliths.

Another POSSIBLE win is if you start having multiple systems, sharing the same component (say, authentication and/or authorization), at which point there's something to be said for breaking at least that bit out of every monolith and putting them in a single place.