Perhaps you're unfamiliar with that structure. I don't think it's common in all Englishes

I am, but it's grammatically insufficient. Idiomatically/colloquially/slang wise, it's fine. I understood enough to know what they mean, obviously.

That's pedantic. Nearly no one uses en and em dashes;

Of course it's pedantic. I'm going out of my way to be pedantic to show this grammar snob what it feels like to throw the first stone.

if they're typing on a physical keyboard those dashes are hard to type

Skill issue. If they care enough, it's easy to find out how. 🤷‍♂️ I use them all the time.

Thanks for joining the fun!