> but given that you have to go digging for the key combination

Except you don’t. If you’re on an Apple OS, by default doing -- (two hyphens) auto-substitutes for an em-dash.

Also, the key combination isn’t even hard. Depending on the layout you’re using, it’s either ⌥- or ⌥⇧-. My fingers press that (and the appropriate combination for apostrophes too) without me having to think. Those ⌥ and ⇧ symbols (and many more) I have mapped to text snippets.

We’re using computers, these things are trivial to do and customise, you don’t have to “hunt” for anything.