You can build something very similar with WebRTC. Browsers already have P2P networking capability, it's just not immediately interoperable with BitTorrent clients. Standardizing some sort of BitTorrent over WebRTC bridge and adding it to BT clients would fix this problem.
That being said, please do not host content this way. P2P blows away the already thin privacy guarantees that the web provides. Anyone seeding the site gets the IP addresses of everyone on that site, and can trivially correlate that with other sites to build detailed dossiers on, if not individual people, at least households[0] of people. After all, that's how the MAFIAA[1] sent your ISP DMCA scare letters back in the 2000s P2P wars.
[0] IPv4 CGNAT would frustrate this level of tracking, but IPv6 is still subnet per subscriber. Note that you can't use individual v6 addresses because we realized very early on that the whole "put the MAC in the lower 64 bits of the address" thing was also a privacy nightmare, so IPv6 hosts rotate addresses every hour or so.
[1] Music And Film Industry Association of America, a ficticious merger of the MPAA and RIAA in a hoax article
I hadn't considered the privacy implications. For this to be workable, you'd need to pair it with near-ubiquitous use of some anonymizing overlay network.
That being said, please do not host content this way. P2P blows away the already thin privacy guarantees that the web provides. Anyone seeding the site gets the IP addresses of everyone on that site, and can trivially correlate that with other sites to build detailed dossiers on, if not individual people, at least households[0] of people. After all, that's how the MAFIAA[1] sent your ISP DMCA scare letters back in the 2000s P2P wars.
[0] IPv4 CGNAT would frustrate this level of tracking, but IPv6 is still subnet per subscriber. Note that you can't use individual v6 addresses because we realized very early on that the whole "put the MAC in the lower 64 bits of the address" thing was also a privacy nightmare, so IPv6 hosts rotate addresses every hour or so.
[1] Music And Film Industry Association of America, a ficticious merger of the MPAA and RIAA in a hoax article