A story, possibly apocryphal, about Richard Feynman: He gave a strong negative review to a textbook that the other reviewers endorsed. When confronted he said he might not be the smartest person in the world, but was he more intelligent than the average of a hundred people? Certainly!
Or from a Car Talk brain teaser: Do two people who don't know what they're talking about know more or less than one persion who doesn't know what they're talking about?
What about 100 or 1,000 people? I'm pretty sure they know less, as they create in their echo chamber greater certainty and additional untruths.
(I am overstating the case for effect; there is value in the aggregate factual knowledge of crowds, and they are not always ignorant.)