OpenAI’s o3 was big on en dashes—one time it produced a Deep Research result containing >200 of them. I’m not aware of any other LLM using them commonly, though. I’d guess humans use them even less often; I don’t think Apple auto-inserts en dashes, and very few people (myself being one) are pedantic enough to bother.
On the other hand, I don’t think o3 was ever a common choice among people copying from LLMs, so en dashes remain infrequent regardless.
In German en dashes are more common than em dashes. I’ve been using them regularly for at least 20 years, both in German and English texts. I never liked it when people just threw in ordinary hyphen instead of an en dash, but few people note the difference.
They're very easy to type on a Mac though (opt+-). I've always used spaced en dashes without realising that that is the more common British style. Unspaced em dashes just look wrong to me.
Unspaced em dashes look wrong too me too in most web contexts, but I think it’s typography-dependency and they look good in serif text when very large and heavy compared to other elements.
On the other hand, I don’t think o3 was ever a common choice among people copying from LLMs, so en dashes remain infrequent regardless.