[phainopepla2]

I have often wondered this myself, especially because the same stylistic quirks are found across models from different labs.

I haven't found a satisfactory explanation, but whatever the explanation is, it is undoubtedly true that LLMs use them to an almost absurd extent compared to the vast majority of human writers. Anyone who reads a lot of prose can see that.

[pegasus]

It all falls into one overarching category: style over substance, quantity over quality. Em-dashes are a simple way to sound important, same for generic throat-clearing phrases like “It’s important to note that…” plus they puff up the text without saying anything, same for overly symmetrical structure like neat triplets parallel clauses, and balanced pros/cons even when the topic does not naturally call for them, etc.

And they don't have a sense of stylistic restraint, so they often go overboard with one or more of the above.

[Delk]

In my (admittedly limited) experience, a verbose and elaborate writing style is also traditionally more common in humanities whereas scientific or technical writing favours a rather more terse and matter-of-fact style.

I don't know about the structures you mention specifically but if you compare an article on humanities or social matters against the style that's common in science and technical writing, chances are it's going to look more verbose in any case.

I don't necessarily have the best AI-dar but TFA didn't ring any LLM bells to me.