You didn't use "-", you used "—”, which is different, and not commonly used, especially when you are in a stream-of-conciousness mode and not caring about fixing other typos, capitalisation or inserting paragraphs.
My last term paper had a 9% score on the AI detector because my writing is so, so, so far from anyone else’s, too! Em dashes and all!
Super proud of that :)
I’ve been thinking a great deal about why that is and have come to some conclusions