Different things though; "catalogued books and other print materials" is not the same as "compendium of human knowledge". The former is an archive, the latter is an encyclopedia.

You won't find a 1920's copy of a newspaper in Wikipedia, but you will find articles about events from then that link to said newspaper.

Both are super important though, Wikipedia can't exist as it does now without archives (digitized or at the very least referentiable).