I agree, there are legitimate writers who use em dashes often, but I think this tool also helps you distinguish those from AI-generated content. There's a different quality in the way AI generated text uses the em-dash. Often the ratio of em-dashes to the rest of the text is much higher, and it's usually used to complete a point, as opposed to an interjection like you just did in your comment. I think that's easy to spot when you know to look for it.