That's really only an issue for technical topics. Stack Overflow would obviously be a much better source of quality training data for the kind of questions you

That's really only an issue for technical topics. Stack Overflow would obviously be a much better source of quality training data for the kind of questions you presented. But for most things outside of that Reddit is by far the best online source that actually represents answers you would get from real people. Questions like what is the nightlife like in x city don't have a single true answer and thrive due to Reddit's the diversity of thought.