This allows you to view video from protocols the browser doesn’t support with very little added latency.

Things like RTMP/SRT/RIST/RTSP….

Back when I was doing live-streaming the primary reason I wanted it was to eliminate (or reduce) the need for a CDN to deliver chunks to the end-user viewers. I fantasized about a protocol adapter like this that would act has the "host" peer that would stream the video from e.g. RTMP source, which would then translate to WebRTC for all the viewer peers in a P2P fashion.

I don't know if this actually works like that, but it's fun to think about this being the missing link I wanted all those years ago.

It looks to me like an early WIP clone of those "watch movies together with friends online" services.

it might be useful as a preview for media ingestion