Call of Duty: Modern Warfare's large file size is due to high-quality textures, detailed 3D models, extensive audio files, and multiple game modes. The game also includes a variety of maps, weapons, and character customization options, all of which contribute to the overall file size.
A new update to Activision's Call of Duty: Warzone requires users to give up 100gb of their hard drive space as well as just a teeny bit of blood. The file sizes are big, but that's because the game is big.