You have plenty of literature that can act as ground truth. This is not a terribly hard problem to solve, it just requires actually focusing on it. Which so far simply hasn’t been done. ChatGPT is just the first “look, this can generate text”. It was never meant to do anything useful by itself or stick to the truth. That all still has to be developed. ChatGPT simply demonstrates that LLM can process natural language really well. It’s the first step in this, not the last.