Agree. Fancy' words can add flavor to the writing and help avoid repetition, and also are more precise. If you are writing warning labels or instructions, then maybe simpler is better. But otherwise, I don't think it is a problem..
As a reader I would prefer the writer not repeat themselves and write less, rather than try to find some fancy way of not “sounding” repetitive, but in reality finding yet another way of repeating. I prefer actual repetition to that.
More precise words aren’t always better either. Having someone easily grasp what you are saying works much better for conveying information.
Complicated writing is lazy writing.
“If I had more time, I would have written a shorter letter.”
And to make a point that perhaps is restating yours, or overlaps with yours, I think some good writing is "dense" the way that certain foods are calorie dense.
You can intentionally write in a way that's different from your natural voice if your goal is, say, information density, or expressiveness that conveys personality or that makes the experience of reading more enjoyable, or to allow writing to shimmer with all of its contextual entanglements.
Of course people can attempt to do this and make a reading experience worse, and I think writing how you talk can be a helpful rule of thumb for certain use cases.
