I like wikipedia, but I always felt like it was missing crucial pieces of information to make it the "sum total of human knowledge." For example, I can look at the articles for ISO_31-11, Spheres, and Sphere Eversions, but I don't think that information alone is enough for me to go from "society of post-apocalyptic 'we lost how to do math'" to "we can prove sphere eversion is possible once again." I chose this example because I'm shit at math and never learned much of it anyway so I can maybe be considered a mad-max post-apocalyptic uneducated peon? Anyway point is I think there's the crucial "teaching" step missing.
Perhaps with a collection of a great deal more articles together, the result "prove eversion is possible" can be taught, but missing for example the ISO_31-11 article alone would make it monumentally difficult, I feel.
https://en.wikipedia.org/wiki/ISO_31-11