I have found LLMs to be very good at the kind of code -> diagram task presented here. Fire up superwhisper[1] and stream-of-consciousness away about why you want the diagram, which bits are important, who the audience is, and so on. Then iterate a few times. Works brilliantly for even very complex things, including 5000 line CDK files.
It's disingenuous to conclude that AI is no good at diagramming after using an impotent prompt AND refusing to iterate with it. A human would do no better with the same instructions, LLMs aren't magic.
This is the same as my previous comment https://news.ycombinator.com/item?id=42524125