Comment by RevEng

Exactly this! Many times I read an article that someone says is "obviously AI" and lists several tell tale signs, but these are patterns I also follow in my own writing. I guess that makes me an LLM? These are patterns I was taught for years in school, both in high school and in college level technical writing classes. They may be tropes - or rather patterns - but that's because they were taught en masse to students across North America. Like you said, to really sound like an average person, the answer would be to write in an inconsistent, meandering way full of logical fallacies.