The U.S. Copyright Office seems to be living under a rock and completely unaware of how much creative work goes into prompt engineering, as well as selecting the subsequent image and applying variations to it until it meets the human's creative desires.
> While some prompts may be sufficiently creative to be protected by copyright, that does not mean that material generated from a copyrightable prompt is itself copyrightable.
The prompt is fully copyrightable but the output isn't.