I am annoyed that correct use of punctuation is now considered a red flag.

Like all punctuation: it's a choice.

One that has made it's way into LLMs because they've injested a lot of actual books that were professionally type-set.

Humans typing online don't tend to use em-dash; LLMs often make the choice to do so.

That makes it a very strong signal.

I use the em-dash and en-dash pretty often—as many academically-styled human authors do—and sometimes I worry my writing style makes my content seem like LLM output. I tend to use it more when I've been using a lot of parenthesis for lists or elaboration (eg. & ie.).

I've found the most telling sign isn't just the presence of the em-dash, but the fact that the em-dash is used for everything, regardless of wether a parentheses, comma, or semi-colon was more appropriate.

Often the em-dash is used "incorrectly" such as the example above where there is a single space on either side of the em-dash and sometimes it is used in place of the en-dash for number ranges too. I regularly have to fight things like ChatGPT to use other "advanced" punctuation in place of the em-dash.

Also line breaks, LLMs love markdown line breaks for some ungodly reason.

That's my pointless pontification for the day. :)