TLDR:
This is due to the increased amount of content available day one, including open world Zombies, support for item carry forward from Modern Warfare 2, as well as map files for current Call of Duty: Warzone. (Note: as part of our ongoing optimization efforts, your final installation size will be actually smaller than the combined previous Call of Duty experiences).”
I would understand a 100 or so GB but 230 for something like Mw3 sounds a bit bloated.
Even GTA 5 is smaller and has probably more nooks and crannies than the first map of Mw3.
Game size are not determine by the size of the map most of the time but the amount of assets you kept inside the shipping build. Usually the size of the files ranked are textures, audios(especially if you support multiple language), cinematic (pre-rendered), animation.
edit: MooseBoys reminds me how much cosmetics we have now in our games.
edit2: If game engine allows artist to paint over game world and save painted virtual textures tiles for location decoration purpose, texture will scale with game map size, see my response below using BG3 as example.
Will be interesting what GTA6 will bring to the table. The visual fidelity will probably surpass and be as big as RDR2.
If GTA6 doesnt surpass MW3 I feel like it has no place to be bigger. Even if MW3 supports multi-dub, cinematics, etc.