Wikipedia is a perfect example of what I'm talking about, because it's controlled by a very small number of elites with no accountability. This is true of Britannica, but the difference is that Wikipedia editors have perversely managed to co-opt populist democratic rhetoric in order to justify what is effectively an oligarchy. The presence of the edit button on each page functions as an ideological mystification to conceal the where the real power lies. What's happening is that we are provided with the illusion of power, on condition that we never actually use it. As soon as you actually try to become a wikipedia editor, you are immediately confronted with a co-ordinated power bloc that is virtually impossible to penetrate. So far, these elites have been benevolent, but the case of one poweful Wikipedia editor who was a member of a cult and deleted any criticism of the cult leader on his page illustrates that abuse of power is possible.
Another example of this is restaurant reviews. The basic argument is familiar: a single restaurant reviewer in a newspaper is an elite, and this creates the potential for abuse of power. He could demand kickbacks from restaurants to ensure positive reviews or promote his friends' restaurants at the expense of competitors, and so on. Decentralization is proposed as the solution: instead of a single restaurant review, individual patrons review restaurants on a web site and it averages the reviews, and even if a few of them are corrupt, it's much harder to subvert the system. So problem solved, it's a much more trustworthy system. Except for one minor problem: Yelp implements this idea, and restaurant owners have complained that Yelp has abused their power by trying to extort advertising dollars from them by threatening to delete positive reviews and post negative reviews.
The pattern should be clear: moving from a centralized system to a decentralized network doesn't eliminate power, it just moves it to a different place where it can be potentially abused by a different group of elites. That position of power comes from controlling the protocol which aggregates each individual node on the network. The nodes can be decentralized and distributed, but the cost for this is that they must all speak the same language to connect to each other, which is a centralization at a different level.
That's why further decentralization doesn't solve the Yelp problem. We could imagine a federated system of restaurant reviews where individual reviews are stored on servers controlled by individuals, so they can't be deleted. But this just moves the power to a different level - the system for aggregating the peers on the node becomes the position of power, which could potentially be exploited for power and money to an elite. A similar relationship exists between Facebook and Diaspora. This is why Google promotes decentralization, because it is the centralized place you have to pass through in order to get to all that decentralized content, and there's lots of money to be had in owning that position. The handful of multinational corporations that control the internet backbones are also in a similar position of power, control and profit. This is ideal position to hold power, because the average person is completely clueless that these are positions of power. Think of how few people are aware of the importance of network neutrality, for example. Evgeny Morozov makes similar points in his TED talk entitled "How the Net aids dictatorships."
Really, the people promoting decentralization as a moral imperative are the ones who are profiting from it, from VC backed startups who stand to make millions or even billions of dollars to global multinationals who already are. Here again, the idealistic hacker ethos and ruthless corporate capitalism turn out to be one and the same, a nice example of the Hegelian coincidence of opposites.