I found the page Wikipedia:Signs of AI Writing[1] very interesting and informative. It goes into a lot more detail than the typical "em-dashes" heuristic. [1]: https://en.wikipedia.org/wiki/Wikipedia:Signs_of_AI_writing
"Thus the highly specific "inventor of the first train-coupling device" might become "a revolutionary titan of industry." It is like shouting louder and louder that a portrait shows a uniquely important person, while the portrait itself is fading from a sharp photograph into a blurry, generic sketch. The subject becomes simultaneously less specific and more exaggerated."