alt Hacker News> It has a name. The Rule of Threes. https://en.wikipedia.org/wiki/Rule_of_three_(writing)
I don't think that's exactly it.
Speaking of LLM-writing in general, it seems to greatly overuse certain types of constructions or use them in uncommon contexts. So that probably isn't so much using the rule of threes, but overusing the rule of threes in certain specific ways in certain specific contexts.
I don’t necessarily doubt you or the grand-parent comment, but if it’s ‘obvious to even the most casual of observers’ (as my father would say) then it should be easy to have hard data.