Declarative works better than imperative only when someone has already defined the imperative process that takes you from any given state to your goal and does that for you based on your declaration.

Google maps works great for a set of origins to a set of departures for certain modes of travel. Once you get outside those bounds, it can fail in significant ways.

Thus the entire premise of the article thus seems to boil down to: If someone has already done the work, don't re-do it.

The problem with declarative configuration is that as the systems they manage become more complex, inevitably you leave the bounds of the solved problem and have to start solving it for yourself imperatively.