Call of Duty: Modern Warfare launched with a rather insane storage requirement of 175 GB. The next such space-hungry title is Red Dead Redemption 2, with 150 GB. However, the updates that were released for Call of Duty: Modern Warfare since its late October 2019 launch have managed to push it past the 200 GB threshold.
The game consists of three main elements: a single-player campaign, the Warzone battle royale mode, as well as the cooperative Special Ops mode. Console players can choose to uninstall certain modes, thus being able to have improved control over the amount of storage space used by Call of Duty: Modern Warfare. Sadly, that's not the case with PC players, who often have to wait for long hours to download patches that often exceed 10 GB and add elements that they will not be using at all while playing the game.
Those gamers with ~250 GB SSD drives that were able to run Windows and install Call of Duty: Modern Warfare on the same drive can no longer do that and it looks like even dedicating such a drive entirely to the game is no longer a solution. These being said, remains to see how far will this story go by mid-2021: 300 GB+ needed to install Call of Duty: Modern Warfare and the next two-three patches?