> there is no em-dash on a standard keyboard. The one way it ends up in real writing is (…)

Then you proceed to list multiple ways to do it, but neglected to mention that by default on Apple operating systems they are inserted automatically when typing “--“. It’s something you have to explicitly turn off of you don’t want it. On Apple mobile operating systems you can also long press the hyphen to get the option. Em-dashes are trivial to type.