[Satoshietal]

Flowcharts are stupid. Simple systems can be internalized (kept in your mind, perfectly), and complex systems are too complex to graph to any human scale size or useful purpose. These two categories do not overlap. They apply recursively all the way down. Waste of time, no value.

[wmil]

Flowcharts are waste of time.

But diagrams can be very helpful. The important thing to remember is that "a complete map" will be too noisy to be useful.

A diagram can describe a few parts of a complex system quickly and easily.

[sigsergv]

Flowcharts are a great documentation and vizualization tool, if used properly it greatly reduce time required to understand system processes and behaviour.