I looked it up and duplicated data is pretty rare to find in recent games, it received a lot of attention when Bethesda did it for Oblivion, but developers countered it with installs. Games are so big because there is no penalty if they don't compress textures, audio or pre-rendered cutscenes. Why lose 10% texture quality or 80% video quality by compressing a file when you know it is going to fit on the disc regardless.
I don't know why the digital versions of PS3 games are still the same size, but I think it's because it needs to be identical to the disc version, maybe because of the developers choice or obstacles they would have to get over if they want to compress it.








