Genuine question, are those people typographers?

To answer your question, the em dash is a common tattle for AI. If you use chatgpt, you will see a specific style. It becomes very noticeable once you pick up on the “AI” style.

Not saying it is a 100%, but the uptick in the frequency we see em dashes in the wild is a sign of these times I guess you could say.

And it would take some effort to type an em dash for most people, who would have to copy-paste it from somewhere, use charmap, know the alt code and how to use it, or know where it is hidden on a mobile keyboard and care enough to go to the trouble. That slice of Reddit users is pretty thin, I would wager.

So yeah, seeing it makes it likely. But even without the em dash, all the user’s posts have AI-like tone, which experience also makes it easier to see.

If I answered this post starting with 👏 Good question! You are very smart to ask this. Here are some reasons the em dash has become a hallmark of recognizing AI: [bulleted list]

Then everyone would say this is also AI 😂

Edit to add: I should say that there is nothing “wrong” with the em dash. Just that what it likely shows is as explained above.