It is not even about YouTube data rates but about display media limitations. There is not going to be any sort of realistic scene data going over the wire just because of that. 99% of it has to be discarded because it cannot be displayed. It cannot be discarded automatically, because what should be discarded is a creative decision. Even if you could compress 5+ gigabit per second into 20 megabit per second losslessly, it is a pure waste of CPU.

Also, noise is desirable. Even if you magically can discern on the fly at 30 or 60 fps, and at 5 gigabit/second, what is noise and what is fine details and texture in a real scene, which is technically impossible (remember, it is a creative task because you cannot automatically determine even neutral grey), eliminating noise would result in a fake-ish washed look.