I've noticed the same issue with AI coding, where you start to write requirements and then realize that you yourself don't have a perfect idea of what exactly this feature should be, or how it should work. It's easy to say the answer should be to simply think harder, or enter a dialogue with the AI about missing details, but if you try that you'll find yourself supplying an enormous amount of context you didn't expec…
Part of the fun of software development is exploring the solution space by implementing, and gaining a deeper understanding in the process, as well as coming up with the corresponding design decisions.
It seems that with current AI, in order to steer it and evaluate its output, you would have to build that deeper understanding up front without doing the work, which seems difficult.