Excellent idea. But the only way I could see this happening is through digital identity. If content has been posted using Civic to access a certain platform, then the author could use Civic to prove his/her identity to the blockchain and claim rewards. We could use something like Oracles but that'd only work with popular content creators that is easy to verify. Other methods would be too much of a pain.

Eventually we'd come to a point where your idea could be properly implemented. James Cameron had to wait a long time to make Avatar.