>There is no greater joy in life than typing a sentence, realising it needs a clarification, a caveat, an addendum — but in the same sentence, not a new one — and, guess what, the em dash is right there for you.

this is several sentences bound together in a rat king and furthers my theory that the use of more exotic punctuation like em dashes is the linguistic equivalent of a code smell. It may do the job, but it strongly indicates that your writing would benefit from rephrasing the entire sentence.