Sometimes the pixel perfect details don't matter for a use case, so why set the hi-fi expectation for both the designer and developer. The designer can get caught up in choosing colors and pixel-perfect layout, and similarly the developer implementing on that design might unnecessary time attempting to match the hi-fi design.
If anyone watches "Meet Kevin" youtube channel, you would know the bad publicity Apple gets with him attempting to stream on his relatively new Mac Pro system. Any effort to improve that capability would be in Apple's best interest. Streaming is not going away.