How many models have you tried? They write very differently. I found Gemini Argon 4 to be really good at writing like a human. Simpler models like Haiku seem better than more powerful ones like Opus, though even Opus has improved considerably with 5.5. DeepSeek is much more roundabout which can mirror certain people’s styles and some people prefer that. So in summary don’t just say LLMs are bad at writing, you need to be more specific: which model, which style, which context, what instructions were given? Claiming they are bad under all combinations is just ignorant.

> I think a partial root of why AI writing is so bad

I hard disagree with that statement. At shorter outputs, with proper prompting AI produce very decent writing.