Yeah I think CAD is a perfect domain for this kind of thing, and IIRC that was one of the original target applications for Sketchpad, where Sutherland demonstrated constraint-based bridge design where the constraints were sketched in.

I agree I don't think LLMs really change the equation much.

For another look at where drawing-based programming has gone, see Dynamicland by Bret Victor. No LLMs required.