Robots, you can’t have it
Lately, one of the most popular ways of diagnosing whether writing has been produced by an LLM rather than a person is by identifying the excessive use of em dashes.
The em dash is a delightful little bit of punctuation, used well: that is to say, with restraint and cleverness. I do wonder what it is about spamming the em dash that has become a particular tick of GPT and friends, but I also don't care.
This article from the Nitsuh Abebe at the New York Times gets at my discomfort with the discourse around the em-dash quite well.
Part of what makes them popular, in fact, is that they can feel more casually human, more like natural speech, than colons, semicolons and parentheses. Humans do not think or speak in sentences; we think and speak in thoughts, which interrupt and introduce and complicate one another in a neat little dance that creates larger, more complex ideas.

The debate about ChatGPT’s use of the em dash signifies a shift in not only how we write, but what writing is for.
The digressiveness, logical recursiveness, and self-reflexiveness that marks so much great writing is inefficient and ill-suited to the "talking" sort of writing that Abebe identifies as all the things that were formerly speech that we have now offloaded to typing into the internet.
I submit that the excessive use of em dashes wherever it appears is a mark of an amateur, human or machine. But don't tell me a whole-ass piece of punctuation is off-limits just because it is inefficient for business communication. How boring!!