The reality is that humans have a rough sweet spot for the amount of complexity they can reasonably consume, and a high-level, somewhat vague diagram that has b

The reality is that humans have a rough sweet spot for the amount of complexity they can reasonably consume, and a high-level, somewhat vague diagram that has been cherry picked by someone who intimately knows a system is a great introduction. This is not to say that blueprint-style UML has no value, it's just comparatively rarer, since it requires much more time investment. However, the two do not address the same needs.