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.
There are also em-dashes in a huge number of their articles. I didn't spend time picking one. I just went back to the oldest article in the first category I picked, and found one on the first try. It's a common style for more "serious" magazines and always has been.
> 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.
No, thinking they do is like having read a lot of literary text and being aware of how it has a long history of being used in serious writing.