Is color banding usual problem in commercial released movies? for very long time I have used two machines - one with good monitor for work and one with "ordinary" monitor for fun/movies/games.

Recently I unified this with high end mobile workstation with very good display with almost full sRGB coverage.

I immidiately noticed significant color banding in Youtube and movies. For Youtube I am sure that this is caused by compression and color space conversion. 

But is this usual to happen in standard commercial movies? Especially animated movies with very dark scenes/moon light looks really bad on my new monitor. I compared same movies with old monitor and it looks that its limited color space sort of "smooth" these artefacts  out. 

Are movie studios really that desperate to save streaming bandwidth and disc size to hope that there are not many people with eagle eyes who will criticize those few dark scenes in movies?

I know this is sort of subjective question, but hope someone have other/another opinion from experience.
It really depends on the distribution medium. Many are very low quality. 

Most consumer distribution is 8 bit, but when a studio masters a DVD, they'll put a lot of effort into making that specific content look good. That doesn't happen for streaming.