There’s a blockchain-based Reddit clone called SteemIt that I had a cursory glance at. The idea of it is that you can make money (specifically their cryptocurrency) from posts because of how site activity mints more stuff on their blockchain. Unsurprisingly, SteemIt is also unusable and has been astroturfed by spammers.
Reddit would kill their platform overnight if they allowed users to tip posts whilst simultaneously chasing away community moderators.