User rating system for question difficulty

The question difficulty level (easy, medium, hard) is never accurate and if we mess this up it can have huge effects on student motivation (I've heard many times "I can't even answer an easy question" when the question is not that easy)

not for the fault of any developer: it is actually really hard to accurately assess how hard something is

could we implement a reddit-voting style system for difficulty?? Like an upvote/downvote feature? or just ask the users to tell us how hard the problem was. Maybe average completion time if we implement the issue on a timer per question? Would be very fun.