As I said, consensus doesn't make reality, only indicates it. Sometimes the consensus is wrong - in the middle age, consensus was that the Earth is in the center of the universe.

But it's still the best indicator we have. And consensus is measured by numbers, so Amazon rainforest guys aren't really more meaningful than flat earthers, alien abductees and scientologists. Of course, number is only a shorthand - in the age of modern science, all knowledge about reality must fit into the general framework that explains and predicts reality in order to be worthy of being considered true, regardless of how many people believe it. But that boils down to consistency again.