I've learned more about the real world around us from Quora than I have from almost every other source. Only Stratfor rivals it, and that's only in the realm of geopolitics.
Of course, you'd learn more at an actual military academy about strategy, but Quora does the work of getting the people that already went to those academies to boil down everything they learned into short, readable essays.
In fact, I'm finding that I'm reading fewer long-form journalism articles and blogs because I find Quora so compelling. Those were my previous bar-none best source for information.
Nothing beats curated long-form journalism for variety, but there's still a lot of noise and the work of separating it out is onerous enough and Quora is easy enough that I've already subconsciously switched, not bothering to maintain my RSS workflows. If I want some variety, I'll fire up Feedly or Pocket and pull out a few articles, but generally I'm looking to iterate on my high-level model of how the world works, geopolitical analysis from Stratfor and watching smart people answer stupid questions at Quora is the best bang-for-the-buck I've encountered for that. HN is the best place for business-specific information, if it weren't for that I'd have moved on a long time ago, I've been so far unable to find a good vein to mine for business on Quora, though it's half-decent with finance, though HN still beats Quora there too.