It sounds like you haven't tried.

LLMs definitely can do this. The output tends to be overly positive though, claiming that any sort of rough draft you give them is "great, almost ready for publishing!". But the feedback you can get on clarity, narrative flow, weak spots... _is_ usually pretty good.

Now, following that feedback to the letter is going to end up with a diluted message and boring voice, so it's up to you to do with the feedback whatever you think best.

Btw, this is precisely what I implied.

I never ask the LLM to evaluate my text in terms of being good or bad. Instead I try something like this:

"In this section I tried to explain X, I intended to sound in Y and Z fashion, and I want a reader to come out with ateast W impression. Is the text achieving these goals? Do I communicate my ideas clearly and consisely, or are they too confuse and meandering?"

I typically get useful feedback. I preface specifically asking it to not rewrite, simply pointing the bits that it finds faulty and explaining why.

Of course the prompt is different is I am writing, for example, technical documentation, or if it is an attempt at creative writing.