At least right now it's mostly in AI-related articles. Scroll any AI article and have a look at the number of topic headings as well as how many start with the word "The". I have my defenses up on any AI articles and can quickly avoid the are LLM-output with aesthetic clues. An upfront disclosure would of course be better.

Unfortunately other topics are still catching me off guard, like the article about complex numbers posted today which I managed to get through a third of before realizing all the grating bits I was reading were because it was from an LLM.