Also ChatGPT is only knowledgeable about general things, but even there it makes errors. It's basically a very complex scraping algorithm, the more interesting part is the language generation; even then this stuff seems at least unethical if not illegal since it's using other people's work/research without citation.
Who checks if that book actually exists and is not made up? Especially if it's not a highly politically charged topic.
And then there are circular citations. Someone posts unverified/false info on wikipedia. Then it gets cited by some blog or other media that wikipedia considers trustworthy. And that then gets added to wikipedia as a reliable source.