Maybe the people or colleges who publish these "essays that worked" want to make it seem representative of what their agenda is.

If you've taken a look at AP english lang/lit/history sample essays that got a 9 (or whatever the perfect score is, I forgot lol) they seem to have very similar structures. Thesis statements are lists, and are mostly in different sentences. However, my Lang teacher always told me to write a 1-sentence thesis, and never make it a list. Like don'y make it be like "this author uses x, y, and z to demonstrate that __" even though every sample essay I've seen has shown that we should be simple. I'm pretty sure there are way more other styles that can get a great score, for the sake of simplicity, they publish one standard essay to make their grading seem more standard.

I think in the same way, those colleges will probably try to make their students seem like the greatest people. They want to make their general overall student body seem amazing and talented a whole lot of things, like essay writing, even when it's not the case. I'm sure there are other essays that don't sound like they were made by rhetoric majors. That's why I liked the UC essays better. You literally don't have room for fluff, and you need to prioritize who you are above how you write about it. But even in the longer commonapp essays, if that's your style, then just go ahead and do it! Don't think lowly of yourself because it's not similar to the samples, because it's not supposed to be similar at all.