I think this image encapsulates it.
The purpose of librarians is to hit the local minimum of that function, where there is enough information to help someone understand something without there being so much information as to be overwhelming.
(Of course there are exceptions. In academic research, for instance -- though this may be a bias of my background in academic English -- I think there's value to being at the right-hand side of the graph, with lots of information and lots of confusion. The point there, after all, is to move through the confusion to a new synthesis of knowledge that explains and incorporates the information you have.)