I really hate the "em-dash = AI" myth. I've probably been typing em-dashes since before half of y'all were born. I am not a cat bot. I will not cede the em-dash to AI!
As with most ills of the tech world, I blame Microsoft for this. Windows makes it unreasonably difficult to type em-dashes (and most non-ASCII characters, really), which is probably why most people don't. It's always been easy enough on Macs going back to the 80s — option-shift-dash. It's easy on iOS and Android too. Linux is a mixed bag, I guess — I've edited my keyboard settings on Linux and I forget the defaults on different distros/DEs.
At least AI doesn't use parentheses as much as I do. I've still got that going for me.

Oh, I hope it didn't sound like I was arguing with you. Your post was totally reasonable. I'm just venting at the subject and the state of the world. :)