I did not know option + shift + hyphen produced an em dash. I've always used a double hyphen as a stand in -- as I did just now. LLMs don't do it and I haven't been accused yet. Though, more likely, I'm not popular enough for people to notice!

The overemphasis by critics on punctuation and "this not that" is tiring. I don't really know how to describe LLM writing but it has the same qualities as flat soda. Some authors you feel as though you fall through their work with little effort; unable to stop until gravity slams you into their conclusion. LLM writing can feel like an uphill hike to a sewage treatment plant. That is, its easy to convince yourself to stop at any time. There's a positive quality to that. I hope AI labs don't find a way to remove it.