I don't think AI could make someone a better writer, I wouldn't even trust it with grammar since we've already since a drop in it's ability to do math problems. But back to AI not helping you become a better writer. From what I understand with things like ChatGPT is that is is just predicting what is most likely to come after each word, which means that it will always weight and outcome to the most likely which would flatten and reduce your diction. Asking it to do things in the style of certain authors invites issues with it just spitting said author back at you.
Personally I think the AI bubble is going to burst in a couple of years and people are going to lose a lot of money. It's already a losing money and has yet to produce anything that can make a profit. There might be some edge cases where it could be useful, I don't know what they are, but the way it's being pushed more and more is just desperation as the technology is running out of usable training data.
Just read and write more if you really want to be a better writer.