I use the em-dash a lot. It’s not just about the presence of one, the issue is that LLMs know they exist but don’t know where they go. It’s sort of like a semicolon, which goes where neither a comma nor a period feel right. An em-dashes simply goes where neither comma nor period nor semicolon feels right

On my keyboard, I just click the button on the bottom left to see punctuation, and then long-press the hyphen