Except when the question is actually interesting and has less about it written, whatever frontier model you are using may confidently give some partially correct or completely wrong answer. Unless you're an expert who wouldn't need to ask AI in the first place, you cannot tell if it's false. "Oh but it's good enough, it's correct most of the time."

This gradual accruing of more and more falsehood will hurt us in the coming years, big time.

EDIT: I just asked Claude a very basic question on an area I'm an expert in and it gave me a partially true and misleading answer. I drilled in on the false part and it wiggled and gave more confusing, incorrect, poor justifications for why it gave me the clearly wrong information. If someone was not an expert, there is absolutely no way they could fact-check this. Instead, the falsehood would be written, published somewhere, and would serve as a base for more falsehood in the future.