Youtube is performant because its http to a geographically close datacenter.

WebTorrent layered over a traditional CDN is the same exact thing

I'm not sure what's so hard to understand, WebTorrent is regular CDN capable with regular HLS chunking... same exact performance, it's additive when it reduces bandwidth costs by shedding chunks over RTC to peers.

Yahoo literally used this for their content delivery at massive scale already, your assumptions are wrong.