You make fair points in that micro services are not a silver bullet, the functional wins I perceive aren't automatic and I intentionally build a service in that way to get the functional benefits.

So yes there is a caveat, if a service doesn't return the same output for the same input then some benefits of the approach are lost. I would like to add an additional benefit for teams of programmers, in that each team gets the ability to build out a service using whichever technology they find suitable i.e language, frameworks etc. Something I personally find difficult to do with a monolith.