Wikipedia tends to be pretty high-level, i.e. focus more on people, events, general principles, high-level summaries of how things are and their history. But in case of a societal collapse, wouldn't that be kinda useless? Not sure what specific pieces of literature you'd want to have on your emergency hand crank emp-shielded Kindle, but I'd expect more hands-on material would be preferable, i.e. material that tells you how to make and do certain practical things and the right technique and relevant caveats.

> An offline copy of wikipedia would be the next most important thing to membership in a community.

It would definitely not be. You're taking Wikipedia marketing waaay too literally. It's not the "sum of all human knowledge," it's a flawed collection of Cliff Notes for some of it. A roomful of undergraduate textbooks (or the equivalent eBooks) would be about 100 times better than Wikipedia as a foundation for knowledge, but neither would be very helpful in solving urgent, practical survival problems.