Perhaps even federated? What would be the pros and cons of such approach?

At the moment, most VPN servers are hosted in high bandwidth locations. However, the servers are still "centralized" in many level the least which is ownership. Of course, a decentralized VPN service crosses lines with mesh networks and peer-to-peer architectures that potentially make the need for VPNs useless. The thought, nevertheless, might still be worth exploring. Let me know how you think about it. Thanks