Centralization is always destined to failure because growth requires catering to an ever lower common denominator. When services are new they are exclusive and

Centralization is always destined to failure because growth requires catering to an ever lower common denominator. When services are new they are exclusive and content quality is high, if narrow. As they scale their standards drop, it is a mathematical certainty. This is the fundamental mistake of Web 2.0. It's impossible to be everything to everyone. In other words content moderation is a feature and if you can't do it while keeping your audience happy you are too big.