In broad strokes, I agree. You still have to make decisions and apply taste. It's _extremely_ unlikely that you'll have the full spec and shape and architecture of something large fully settled in your head before you start.
It's also unlikely that you're going to make those realizations, expressions, and decisions when your harness is asking you to choose between what _it_ identifies as being important decisions. If you're in the loop you're getting dumped on with lots of stuff that barely differentiates and you're biased away from catching things that matter.
If you're in the loop, use the loop. It's not a terrible construct. It will give you a mediocre outcome. And if mediocre is sufficient, you're done.
And here's the part that didn't make it into my prior comment -- if mediocre isn't sufficient, _stop the loop_. Play with what you've got. See how it behaves. Explore the edge cases yourself. Sketch how it works on paper, and how you want it to work, and think about how that should be constructed. Use your brain.
Then write a really long prompt (maybe referencing your files and notes and assets) to get back into the loop again.
I guess what I'm ultimately getting at is that the loop is useful _and_ a mind-killer, and using your mind is _also_ high value, so do both those things, but don't do them at the same time.