You want your rough drafts to have a roughness that conveys your level of confidence. If your AI first draft looks polished people may feel more pressure not to deviate.
I find these hand-drawn Taxi Drivers storyboards very charming even though they obviously don't map cleanly to shots in the film. This is what you're giving up if you just tell an AI "give me a close up of Travis Bickle's face"
https://boords.com/blog/martin-scorseses-hand-drawn-taxi-dri...