Decentralized internet proponents won't like to hear this, but network operators would much rather have CDNs for distributing popular content than any P2P approach. It just uses less overall network bandwidth.
My understanding is that a CDN for video improves performance and reduces traffic for the host but the total bandwidth doesn't change for the client, so for a network operator it wouldn't make any difference.
In contrast with p2p, bandwidth may or may not be saved for the ISP. If my peers are close to me, sure, but if all my peers are US based, then there is no bandwidth savings. Furthermore, when I stop stream the video, and I don't have parts any more, and another in my area is still watching, they now have to connect to US peers and/or origin server.
This is obviously oversimplified. In reality, the best solution likely includes a CDN combined with P2P, which would maximise bandwidth savings for hosters and maximise performance.