For me, those small differences in punctuation do affect the tone of what I'm reading.
I've used em dashes for long time now, but only sparingly. I learned about them in a scientific writing course but obviously I had seen them before knowing whay they were called

Like this anon says (>>105858078)
It's used a lot in literature but I suppose some of that h
got lost in translation when our primary medium to consume writing became screens and not paper. (I was an on/off avid reader growing up)

this is subjective, but to me, an aside is better expressed through an en or em dash than a double hyphen