I feel dirty using emdash as the discriminator between human effort and non-effort. But it sure has quite a few.

I've been using the em-dash for years, having started doing so well before the dawn of LLMs -- needless to say the fact it is used as a telltale sign of LLM writing, doesn't gladden me one bit. Also because I value concise writing through picking correct grammatical elements -- like the em-dash.