I'm surprised that sites that serve videos--like YouTube and Netflix--haven't already come up with this idea, of using a codec optimized for transmission over t

I'm surprised that sites that serve videos--like YouTube and Netflix--haven't already come up with this idea, of using a codec optimized for transmission over the network. I wonder if we can do this with WebSockets? (The decoder might need to be in WASM for performance to be worthwhile.)