Stack Overflow on Steem - has anyone built it❓

I wonder if this has been realised already. Its kind of a nobrainer 🤔 to combine a QnA system like SO with a platform like steem.. getting rewards for answering technical questions.

A little research on that topic led me to some posts about the idea about a year ago. Feedback was always positive.. but I couldn't find any live project trying to do that. Why?

I don't know if these to 2 things really fit together, especially the reward system which would focus on comments (aka Answers) who should get rewarded more than the Post (aka Question).

Anyone can elaborate more on this❓