I've been using em dashes since long before LLMs existed, and I won't stop. Some people might think it's a sign of an LLM, but I know it's just a sign of their own short-sightedness.
It's really frustrating to have to adjust my writing style to seem more human despite being entirely human. Many of us have been using em dashes for a long time, who else do people think the LLMs learnt it from?
Em dashes are fine in throwaway casual writing like internet comments or tweets or whatever. However, I think that, in any writing that is significant enough that LLM usage is scrutinized, they often just come across as a crutch to avoid more planned out sentence flow. I think it's actually a good thing that people are feeling like they should cut down on them.
Wrong. They show up in some of the best and most widely and intensely read prose that exists, with good reason. Of course, like any tool, they can be misused by people who don't know better.
This issue, as I understand it, is about the actual choice to use an emdash character (—) rather than a hyphen (-), and about the effort involved in doing so. It's not about sentence structure.
I don't really understand how AI developed a bias towards doing it correctly rather than doing it the lazy way. But hearing so much about emdashes qua LLM detection mechanism eventually just got me to decide that typing an ordinary hyphen really is just lazy. And then I ended up configuring my system to make it reasonably easy to type them.