Perhaps people have mimicked the style because LLMs have popularized it and clearly it serves some benefit to readers.
It's hated by everyone, why would people imitate it? You're inventing a rationale that either doesn't exist or would be stupider than the alternative. The obvious answer here it they just used an LLM.
> and clearly it serves some benefit to readers.
What?
It could be involuntary. People often adopt the verbal tics of the content they read and the people they talk with.
So, someone who falls on the side of not completely hating LLMs for everything (which is most people), could easily copy the style by accident.