Well I just started using musing.io today. But being a user of Quora, I am familiar with this kind of Q&A platform. The fundamental benefit of such platforms is that it allow anyone to ask/answer any question. Leveraging on the wisdom of the community, good questions and answers get voted up, thereby benefitting everyone.
Versus Quora, the additional benefit of musing.io is that users get rewarded with cryptocurrency, STEEM, when their questions or answers get upvoted. This give people the added incentive to provide quality answers to questions.