[The more people contribute to a shared network, the less appropriate "personal computing" metaphors becomes. It becomes inevitable to index aggregate data on their behalf, and these are shared resources that require governance. Pure p2p fails here because it has no solutions for shared governance.]
[Servers simplify operational challenges that come with p2p, like reliable uptime, device sync, and key management.]
A shared data space enables modularity, separating powers away from the popular hosts.