> Sooner or later, I think companies like twitter or reddit will want to "lock in with golden handcuffs" their most valuable writers, those who result in precious ad money eyeballs.

Reddit already "pays" their writers, they pay them in upvotes. But seriously though, that's how places like Reddit get their content. You want to post because you think "people might like this", and "I might get a ton of upvotes" and "I might even get some awards". Now all of these things are completely worthless, but the point is to trick your brain into thinking those things hold value in an attempt for you to post.