I’m sure it isn’t all just for the OS. Storage space is reserved, I’m sure, for other necessary features, like the PS4 reserves for possible updates or something. Either way, it really does suck these days HDD space is so small with games so big. It’s gonna get really annoying having to install the game, uninstall it to play a new game, then you want to go back and play the first game you have to uninstall and re-install and update the game again. This sure makes me miss cartridges. Lightning fast load times, no HDD needed, and no installs. LONG LIVE THE CARTRIDGE.