There are many situations in which the Eight Fallacies of Distributed Computing, and/or the CAP theorem, would mandate a monolithic architecture, if their implications with respect to the business processes were understood.

There is No Silver Bullet. You just get to choose what kind of hell you want to live in.

The best advice I have heard is that as your code structure will eventually mirror your organisation structure, start by building your code architecture to be compatible with your organisational structure