All of these things are doable without a blockchain if you have a third party you can trust for not cheating in the moderation, in the handling of micro-transactions, for not being bribed by internal or foreign agents.

Look at the fire twitter/facebook are under: Dems accuse them of serving Russian interests, Reps of being pressured by "deep state".

A blockchain-based moderation would be immune to this criticism, the data and algorithm being laid publicly, for all to see and check.