I train many LLMs and there are constraints on what we can output in our writing. Creativity is only encouraged to an extent. Interestingly, in the creative writing competencies I've worked on: non-linear narratives, sentence length variety, and intentional ambiguity are highly discouraged and will not pass before a reviewer trashes them. To me, these are the elements that make creative writing...creative and unique. So, a lot of the "human" element is sadly stripped.

You're mostly right though - we need to remember that AI is not that artificial. It's human-trained, human-generated, and reinforced. At the same time, it's that very reinforcement that can sometimes create a stylistic echo chamber of sorts where we follow an unspoken "style guide" driven in part by constant reinforcement of what is "good" quality.

In conclusion, this undoubtedly generates a tapestry of institutionalized language amongst a landscape of otherwise richer prose, a testament that underscores the vital and invaluable need to create a more transformative journey to augment ideal responses that align with more vibrant, thought-provoking language utilized by more innovative writers in an ever-evolving landscape of robust communication and creativity. It's worth noting that this is not an exhaustive list of why ChatGPT is so easy to recognize. You should always consult with your brain or a trained linguist before delving into any serious writing project. I hope this helps!