Verifiability, Not Truth - "But I know The Truth!"

"But I know The Truth!"

Are you sure that's the case? Many times, when everybody considers something to be one way but you find somewhere else that "everybody is mistaken" and things were actually some other way, it's more likely that you have found a fringe theory. The stance of Wikipedia on such things is to avoid giving undue weight to such minority ideas, and represent instead the current state of understanding of a topic. If there's indeed an accuracy dispute between scholars, it is described without taking part. If there's a universally accepted viewpoint and a tiny minority one, this last one may be ignored.

However, representing a majority viewpoint as such does not equal considering it true, and it is possible that "everybody" is actually mistaken indeed. For example, before Pasteur everybody considered the spontaneous generation theory to be true, and they were mistaken. Even so, if Wikipedia had existed before Pasteur, it should have treated it as an accepted theory.

And in this hypothetical scenario, what if Pasteur fixed the article on spontaneous generation after proving it was wrong? It wouldn't have been accepted. He would have been required to explain his theory in the regular scientific field, and have it checked and approved by peers. Only at such point Wikipedia would reflect changes in the acceptance of the theory. Why? Because Wikipedia does not know, nor have the resources to verify, if either one is correct or incorrect, or to set apart an unpublished but revolutionary theory from a common fringe one. That's why it relies on verifiability rather than truth.