In my opinion, this isn't a problem of AI. the people who get deceived by this are willing participants in the lie. When proven wrong, they will fall back to the echo chamber and rely on it to give them more false facts. They won't seek information outside of their own circle. They cannot be understood as merely passively misinformed. They are actively lying to themselves.

What you'll tend to notice with "willing participants" is that they're not looking for truth, they're looking for confirmation. No-one asks for proof when you tell them what they want to hear.