It isn't about wide use. It is about a character that almost no-one enters explicitly. Nearly all usages are copy paste, or inadvertent/unintended conversion by an application such as Microsoft Word that converts regular quotes to smart quotes, etc. In that respect, we see that an AI is performing identically to a real human. An AI does not and most likely would not add see a purpose an em or en dash to any text, unless it was an article about em or en dashes, or they knew the person they were speaking with uses en or em dashes.