A lot of time I'm not very confident in what I wrote because I have a tendency to ramble and not get to the point quickly. Reading helps, but it's more about style, doesn't help me express myself more eloquently at all.
Another thing is that I find myself using AI-isms in daily conversations more and more the more I use them to help me code. "Load-baaring" and "not X but Y" are phrases that I actively have to catch myself to avoid using now.
Rambling is OK as long as you can treat the result as a draft that you can refine. I've often written emails that were three paragraphs in the first draft and 5 lines after deliberate revision. And the shorter revision was always much better.
Rambling before getting to the point could be your signature style if you do it well.
Your environment has a huge influence on your language, which is why the advice for anyone writing given here (read, read a lot) is not only sensible but indispensable.
LLM tropes are one thing, but before those came along you could easily see how someone working in a corporate office would pick up jargon there even if they loath it. Here on HN you can observe certain phrases and words which seem to be part of what some IT professionals use — like the horridly angular orthogonal used figuratively.
Reading prose written by writers who live outside of such bubbles (or who simply have a good editor in addition to their own filtering) is an antidote to that.
Working on stylistic issues is a conscious self improvement thing, but you leverage your many hours of reading when you're tackling that. Reading a lot means you unconsciously get good at judging which prose works well and which grates.