Isn't this what https://webtorrent.io/ is?
kinda but i think that's for files. I am specifically thinking for live content like twitch
Trystero can do this: https://github.com/dmotz/trystero?tab=readme-ov-file#audio-a...
You'd need to make a UI for it
The first demo, right on the landing page is streaming a movie from peers.