Suprisingly, then, the blockchain hasn't really created decentralization. It is just changing the chokepoints from the database to the analytics.

This!

Yes, I noticed this even back in 2013 when I first wrapped my head around blockchain technology. The blockchain simply eliminates the risk of data corruption (Byzantine Generals Problem), but no database is enough by itself, it needs a querying system to generate data for analysis and searching.

Steem demonstrates the concept of a blockchain that does not just store the transfer records of a distributed financial ledger, of the issuance of new bills of exchange, plus verifiable records of reassignment of ownership. It shows it can be used to store textual data for a discussion forum as well.

I would argue that it is simply a persistent form of the transient Bitmessage blockchain based email system, though even in this, the voting system is also transient, based on initial post time, for redistributing a portion of newly minted Steem to create a social network system for inducting users into a cryptocurrency network. Really, the discussion forum is an incentive to sign up a large body of new users and raise the userbase fast.

It is a net leak of value, both the fees paid to the Witnesses, the management of the Steem Dollar futures contract, and the Steem Power common stock (its interest is also derived out of inflation, and hedges against this the more you hold) and the rewards distribution. In effect everyone who holds Steem in any form, is paying some amount for the witnesses and the blog rewards, through a slow but definite dilution of the value of each Steem's value. But it serves a purpose that helps support the social part of the system, and highlights the fact that money itself is an early, and primitive social networking system.

When you think about it, smart contracts like Steem Dollars and Steem Power are both simple forms of robots anyway!