AI writing isn't actually all that bad. But it has a very specific style, and there are MANY tells. I use Claude every single day, and it's immediately obvious to me when I'm reading something Claude wrote. "It's not X, it's Y" "That's the reframe" "The gap is" I could go on.
I too like using em dashes, and have been since I learned the keyboard shortcut over a decade ago. I've never been accused of posting ai-written text because of it.
AI is indeed trained on good writing, but it's also trained on bad writing. And it's post trained on specific things that are writing that aren't good or bad for reasons unrelated to style. What you're left with is a one-size-fits-all writing style. Doing math? Doing medicine? Doing anime waifu role play? It all starts from the same generic milquetoast style until you tell it not to. And to me (and apparently many other people) that's super easy to pick out.
I even studied writing in college. I’ve written published books and articles. I can write well. But thanks for the tip!
Beyond that, most AI content is WAY WAY WAY WAY WAY longer than it needs to be to get its point across and is oversaturated with unneeded "mic drop" phrases
The typical highly voted HN AI-written post has an annoying clickbait title, then jumps into a meandering chain of “so there I was” scene-setting, assertions of dubious reliability & relevance, and supposed supporting examples. All punctuated by short, unhelpfully dramatic sentences that would interrupt the high-level narrative, if only there were one.
I’m really curious what “good AI writing” you had in mind. My personal intuition is that for almost any topic, the HN LLM-generated post du jour has a far superior cousin sitting in the archive pre-2021.