Most people really don't care, which is a shame. The sheer quality difference between a 4k digital movie and a 4k bluray is astounding. Hell, oftentimes a standard bluray looks better despite the lower resolution since it isn't being compressed
> since it isn't being compressed
Isn't being compressed as much. All Blurays are compressed either with MPEG2, VC1, H.264, or H.265 if it's an UHD Bluray.
Theres no technical reason one should look better than the other.
Both should use multipass ahead of time compression with a rate control algorithm, and both should have enough slack streaming bandwidth to handle complex scenes with buffering
Even a well-mastered DVD can look better than online streaming.
A 4K movie uncompressed would be something like two or three terabytes depending on the format. I think Arri are the only cinema cameras that can even shoot uncompressed or losslessly compressed, the rest shoot lossy compressed video in their native raw formats.