Uncompressed textures and uncompressed audio for all languages at once (this started with the 8th gen consoles because their shitty CPUs couldn't handle real-time decompression), so a lot of space is being taken up by audio that's never used in languages you don't understand because at some point in the last 20 years the gaming industry forgot how to create checkbox installers.
Titanfall started that, iirc. I wouldn't mind so much if they let you choose which languages you want installing.
At least some of the PS5 hardware is adding compression back again, so of those games are smaller on PS5 than on PS4.
CoD is an unoptimised piece of shit though. Their business model appears to be snuffing out the competition by filling your drive so you can't play anything else. The last Activision game I installed was the Tony Hawk remaster. I have no interest in CoD at all.
I make VRChat avatars and I've looked at the models for COD characters and weapons before.
The sheer amount of material slots on those things is crazy. Like a whole ass material for a tiny texture that's just like, the walkie talkie on a character. It's so unessciary and while excess materials isn't the only reason the game is unoptimized, it's very telling of how much optimizing they actually do (basically none).
btw size of wii u/switch games is pretty impressive.
BOTW is 10-15 gb with all dlcs and updates. (depends on console (wiiu/switch) and exact version)
TOTK is ~18gb and is the largest official Nintendo game
Mario Odyssey is just 5gb
And they look fantastic, though the art style certainly helps a ton.
I generally prefer indie games, so anything larger than 20GB feels huge. Most of the games I play are 5-15GB, and then something like RDR2 or Mass Effect Legendary comes along at > 100GB, which is about a dozen other games worth of space. Yeah, space is cheap and all that, but it just seems so unnecessary to have a good time.
In a small defense of ME legendary, it is 3 different games in one package. Still Annoying, especially since storage space isn't the only factor. Internet speed can really ruin your gaming plans