Same as in the not-P2P Cloudflare world, get the data from the only node that has a copy of it, which would be the HTTP server or the P2P node run by the website owner.
So CDN with extra steps? In your world Cloudflare or anything like it would be in the best position to make itself indispensable for such a network.
Regular client nodes won’t be the backbone of your P2P network these days since many of them are going to be mobile devices. So you are back to a tiered system where you have nodes which are more suitable for hosting (servers) and most suitable for consumers (clients).
Regular client nodes won’t be the backbone of your P2P network these days since many of them are going to be mobile devices. So you are back to a tiered system where you have nodes which are more suitable for hosting (servers) and most suitable for consumers (clients).