And also quality.
I wouldn't think that the copy of some movie Netflix is streaming to me will be 60-100GB over the duration of the movie. Not to mention when their services have issues and you're watching 5-10 minutes of low quality content until it settles and snaps up to full (streaming) quality.
What's kind of an annoying side effect of this is that you have all this fancy new display tech, like quantum dot LED (marketing term, but w/e), or OLED, but it's all pointless because you're just watching it with crappy compression, negating the quality gains.
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