It's sad, because for most people the use-case for an m-dash is relatively narrow—a parenthetic interjection relevant to the topic (but not sufficiently off-topic for brackets), and needing a subtle call to authority—it mostly popped up in academic or pseudo intellectual non-fiction, or in faulknerian ponderous fiction, but also as a hapless crutch for endlesss neurodivergent layers of qualification.

So I am going to claim disability discrimination about this brutal and unjust sudden boycott, on behalf of crew #adhd.

Edit: shits and giggles

They are one of several signs of LLM writing. That said if you've always used them then you do you

Not the person you replied to but allow me to chime in: I've been using em dashes for decades and I will not stop using them because AI has started playing with them—no more than I will stop writing because AI can write too ;)

I'm not going to let LLMs enstupidify my writing.

I'll continue using en dashes and em dashes — they're very easy to type on macos, iOS, and Android.

You're not getting downvoted for the LLM thing. You're getting downvoted for doubling down on a stupid argument. Em dashes -- and en dashes for that matter -- have legitimate uses in the English language. One symptom does not make a diagnosis. English is barely a respectable language in the first place. Dumbing it down even further to satisfy your preconceptions is, simply, stupid.