And you can easily prompt your way out of the typical LLM style. “Written in the style of Cormac McCarthy’s The Road”
That was with GPT4, but my own work with other LLMs show they have very distinctive styles even if you specifically prompt them with a chunk of human text to imitate. I think instruction-tuning with tasks like summarization predisposes them to certain grammatical structures, so their output is always more information-dense and formal than humans.