The storage requirement is inflated. On disk, CS2 takes 33,6 GB (36 090 429 440 bytes), which is less than 50% of the mentioned 85GB.
I understand you would want to have some leeway so someone playing the game doesn't surpass the 'disk space required' within the first three days just because of a few additional maps/skins/textures downloaded while playing... but over 50 gb of leeway given an install size of 33.6 gb?
Maybe pointing towards something else about gaming I don't understand...