alt Hacker NewsHere's an article in the Smithsonian magazine from 1995 with an em-dash:
https://www.smithsonianmag.com/arts-culture/review-of-the-pr...
Where do you think LLM's learned these things from? They are widely used in literary writing. Like magazines and books.
You are citing a single use of em-dashes in a single 30 year old article as proof of something.
If anything, the length of that article shows how rarely em-dashes were used by most writers. They're like exclamatory versions of semicolons, a contrived sudden interruption, a sort of inversion of the three dot "…" elipsis. Maybe the em-dash cracked and fell on the floor.
The reason LLMs use a lot of em-dashes is because that's a format they've chosen for output. Thinking that LLMs have a lot of em-dashes because works in the wild have a lot of em-dashes is like thinking that LLM output has a lot of emoticons because a lot of essayists use emoticons to mark subject divisions in the text.