Downloaded video quality

I posted something along these lines in a comment not too long ago, but I want to hear more people's thoughts on the matter. In my experience trying to find every single cool 360 video there is, in particular computer generated experiences, I've found that even after downloading the video the resolution is really bad. I'm not confusing this with the general quality issues the gearVR faces, because I have found some really good looking videos like invasion (specifically through the FB360 section of oculus video), sonar and "the evolution of VRSE".

However, going through apps like Jaunt, Vrideo, and MilkVR, more than half of the computer generated videos that I download still have really bad resolution, which to me doesn't make any sense. Are these videos just that bad in quality and there's nothing to do about it? There are some really cool fractal videos, CGI shark encounters, and other various computer generated videos in apps like vrideo for example, but when I download them they still look really bad in terms of resolution. I can't wrap my head around why the videos would even be provided in their current state. Sure the concepts of the videos are cool, but the resolution is piss poor for what downloaded content should be.

Again, I have found a number of downloaded videos that look really good so why would, arguably the coolest looking videos, have this bad of a native resolution?

edit: The 3D art section of the oculus 360 photos app has the best quality content I've experienced on the gearVR by far (in terms of resolution and clarity). Considering the types of videos I'm searching for are computer generated, what are the limitations of producing 3D videos of similar quality?