Although the P2P design is theoretically the most scalable, there are several practical issues, specifically throughput, availability, and capacity.

Throughput. The most commonly noted issue is the limited uplink capacity of edge devices, as noted by Leighton in his 2008 article:

Availability. The next major hurdle for the distributed Internet is peer availability

Capacity. If enough users are online for a long enough duration, and they have an acceptable egress throughput (upload bandwidth), all that remains is the question of whether there is enough spare capacity (disk space) available to provide a functional network.

The world is more connected than it ever has been before, and with our pocket supercomputers and Internet of Things’ future, the next generation of the Web might just be delivered in a peer-to-peer model. It’s a giant problem space, but the necessary tools and technology are here today. We just need to define the problem a little better.