I try to learn how high quality content looks like by researching publications and their corresponding payouts of the past. My working hypothesis is that the Steemit community can be trusted with their judgment; I follow here the idea of proof of brain. So whatever post was given a high payout is assumed to be high quality content

Well, with that as a operation basis, failure is certain. That is just a illusion for newbies, not how things actually worked here.