YMMV, but the value I get from producing a diagram is derived from the thinking. Thinking about what I'm trying to draw leads to understanding about where my/my team's knowledge is poorer, what assumptions we're making, etc.

I don't remember who said it, but someone mentioned that mathematics papers don't read well because the models don't know which parts to emphasize and which parts to gloss over. I would imagine similar tendencies here.

Yeah I tend to make my diagrams either as I go, as exploration, or after I'm done figuring things out as a summarizing artifact (and agents are great at using Mermaid to do that second one).

Yes I agree! Drawing helps me think.