The centralization-decentralization cycle is about efficiency vs robustness trade-off at a system level.

When we have a decentralized system that feels safe, we centralize it to increase efficiency. Eventually we have a disaster that convinces us that decentralization was worth it and we re-create it. Then eventually we grow complacent and repeat the process.

When I design a decentralized system now, I just assume it can only live a decade or two before it gets killed and I need to do it again under new branding.