It's much more cost-effective, for everyone involved, in a decentralized platform. All those big company server costs are broken up into dozens eventually hundreds and thousands of different servers just like World Wide Web itself, with websites for each community, right? Communities chip in to buy Little League shirts for their town baseball teams, we set up websites for our book sales and bake sales, school PTAs are able to accomplish great things because their parent communities can afford to help in smaller circles.
Decentralization doesn't just decentralize the data. It also decentralizes the semantics, the funding, etc.