And how does blockchain make this work? By making authenticity too expensive for spammers, you've made it too expensive for 90+% of the population. The spammers/propagandists have orders of magnitudes more money than me.
I suspect that the actual cryptocurrency that wins out here hasn't been invented yet, or it'll be a layer on top of Ethereum. It needs to actually function like a currency, and it needs to give you mechanisms to trade items of value in the real world, goods and services, for future goods and services. None of this "it's just a wildly variable front over USD that you can profit off of swing trades."