Netflix 4K is some bs in my experience. A 4K file of the same show, pirated, is vastly better quality. Whatever they do to it is just vandalism.
Focusing on resolution is like asking "how strong is one meter of rope" without talking about the composition of the rope.
With streaming video, image quality ultimately comes down to the codec and the bitrate. They probably use a relatively low bitrate regardless of codec.
Amazon Prime 4K HDR on the other hand looks like garbage on every platform I've used -- the compression is unbearable in any dark scene.
Not enough to hurt a paid service. Let's say 6Mbps for pretty solid 1080p. And at peak maybe we have .5 streams per account going simultaneously (I bet the real number is significantly lower). So we need 3Mbps per account. How much does a Mbps cost? "Across key cities in the U.S. and Europe, 400 GigE prices range from $0.07 to $0.08 per Mbps."
Peacock doesn't even offer 4K most of the time or on the olympics, but for services that do a $1 upcharge should be more than enough to cover the bandwidth difference.
But acceptable quality can definitely go smaller. Especially if "acceptable" is judged by the significant compression artifacts I see on actual cable TV all the time.
