Your assumption is on the right track. There are ways to use questions, in how they prepare the reader's brain to receive knowledge, that most services are entirely oblivious to. I won't pretend my system is a great advancement, it might fail entirely and accomplish nothing; however, it's absurd how little is actually being done in the space by the major players. I think it's because they largely don't care about knowledge and don't have a true knowledge mission; they're VC businesses playing pretend at it. Quora for example is a clone of a clone of a clone, there's nothing special about it other than it has very modest Silicon Valley refinement. It's the 427th Q&A site in terms of lineage. Their initial one-trick pony was elitism ala FB's Harvard.edu: getting elite people in tech to jump-start it, which pulled in the next tiers of contributors (and they all abandoned it accordingly as it went south, as the elites had no real personal stake in the health of the system; the elites that used to answer questions & interact moved on to posting selfies and stories on Instagram, never thinking about Quora again).

You have the traditional Answers.com Q&A format, which was quasi perfected (maybe as much as possible until AI systems get a lot better) by Stackoverflow. Little has been done with it, mostly what Stack did was aggressively fix moderation and focus on high quality content (and keep the focus there for a long time). You can build a great service just by doing some of those things right, and sticking to it, of course.

You have the knowledge segment technicians, that focus on obtuse, abstract, distant, disconnected technical solutions to structuring knowledge. The semantic Web bullshit (Freebase was a failed product of that) from 10-15 years ago was largely a stillborn spawn of that realm. You still have an army of obsessive knowledge technicians messing with similar semantic Web concepts, having entirely failed to understand the failure of that era and that the knowledge structure isn't even remotely the most important aspect to getting to the proper end goal of maximum knowledge distribution & access. Those hyper technical system efforts almost always die on the lab floor so to speak, and almost never actually impact or benefit the end users: the billions of readers out there on the Internet. It's like living in an ivory tower and never touching the end knowledge consumer. Wikipedia at its heart is a very dumb encyclopedia in terms of its technical structure, and it has done radically more for traditional knowledge access & distribution than just about any other modern service (save Google of course).

The next great knowledge service will probably not be great because it has a revolutionary technical underpinning like a more advanced Freebase or similar. Those efforts will continue to fall flat, because the end reader/consumer does not care about any of that, it's superfluous to what they want. It's like great engineers that can't build great products because they don't understand the user at all and that most people aren't interested in highly technical or complex solutions (tendency toward over-engineering, having no Steve Jobs-like taste or touch for product). Freebase and many technical knowledge solutions put a lot of the technical capabilities in the reader's face in presentation; the key to eg Google succeeding was that it hid all of its incredible complexity behind a single input box of ultimate simplicity. The next great knowledge service will be quasi-dumb in terms of advanced knowledge structure, more like Wikipedia (and or it will otherwise entirely hide its advanced technical structure from the reader and appear dumb / simple on the outside).