[Dn_Ab]

In nature, decentralized networks are more the norm. You find them in neural, gene, protein and metabolic networks. You find them in mycorrhizal networks of forests and in various self-organizing systems. Food webs, IIRC are even more random, as far from centralized as you can get.

These networks with small world properties strike a highly pragmatic balance. They are far more robust to insult when compared to centralized networks (though not so much as random) while having much more efficient propogation of information than in more random networks.