In the last ten years (ever since The Incident) I can think of exactly one problem that seemed to require an arrows-and-boxes picture. It's the dependency graph

In the last ten years (ever since The Incident) I can think of exactly one problem that seemed to require an arrows-and-boxes picture. It's the dependency graph for a project. I generate the picture from a Makefile. Nobody actually uses the picture. We only work on one program in that system at a time, and all we need to know are its local inputs and outputs. The Makefile ensures there are no cycles. It is admittedly somewhat unsatisfying to be unable to grok the whole thing at once. But that's the nature of almost everything in life.