Open up any video editor you have on your PC pop a video file in there and skim through it ...
Now studios 'remastering' have to go through EACH FRAME colour grading / sharpening etc. If they don't and they just run a generic "filter" through the whole thing it will look awful like PREDATOR ultimate hunter edition where they didn't manually go through the scenes frame by frame and the filter just made them look like Madam Tussaud wax statues !
It's a question of is it worth the time and effort and will it make money. But rest assured all the films being made now will look awesome both from a film and sound quality perspective. Cameras can practically see in the dark now so capture a lot of information that can be played around with in post production.