What you're not considering is that software implementation is a 2-way street. The process of reading what you wrote both elucidates something more about the problem, and elicits from you some aspects about the program's behavior that you do care about but didn't consider before.

LLMs for many months have been at a level where if you know exactly what you want, you can simply let the LLM bang out an implementation and never have to read it. But outside of simple problems, you probably don't know what you exactly want.

That being said, I've had considerable success ending every prompt with "ask me for any further details that I haven't considered" or some variation thereof.