The problem with the dash—as you may have noticed!—is that it discourages truly efficient writing.

— One of many of Noreen Malone’s excellent points in “The Case–Please Hear Me Out–Against the Em Dash” from Slate.

Em dashes do seem to tap out the rhythm of modern prose in halting, jarring bits. I like the well-placed em dash, but I will concede that many dashes could be avoided with better structured sentences. Though writing good sentences is becoming a lost art.