This misunderstands what it means to be better at writing. Root cause here is that writing is how humans communicate ideas. An LLM written thing isn’t doing that, it’s something equivalent to copy/pasting a Wikipedia article. Even if the writing gets better, it will still be necessarily empty when expanding anything that isn’t completely specified.

LLMs seem already to be pretty good at translating, where you already have something fully written and are changing the language. It’s when they get rough ideas and fill in the gaps you get the empty prose they are known for.