Game studios learn to optimize your fucking games challenge.
Who the fuck do you think you are? You are a toy. A glorified slinky.
publisher executives will actually tell their studios to have an inflated install size because gamers will assume that Bigger Install Means Better And More Game.
I couldn't find any sources on this, it seems more likely that it's just because optimization costs more than it worth to AAA devs
source: i work in the game industry and coworkers who experience it firsthand have told me this. not to say that optimization costs isn't one factor but. this is certainly another
There's a very good piece of software that compresses games with ***NO DETRIMENT TO PERFORMANCE***
I'd say it's magic but honestly it's just fixing corporate's bullshit junk data
While it's not particularly relevant to people like me who game on Linux (including plenty of Windows games through compat layers like Proton), it really is nice that this tool has such a nice description of how it works. The README is putting the work in to be anti-magical, and I adore it. Long story short, Windows has some built-in features in the filesystem (NTFS) for transparent compression. Which is to say, Windows does the work of compressing data on write to disk, and decompressing on reads, so your programs can be blissfully ignorant about compression logic. Your game doesn't even know Windows is doing that work for it! This has been a feature for a long time, but the algorithms have just gotten better over time. Unfortunately, it's also kinda obscure, so most people don't even know this Windows feature exists.
This also gives you an idea why there's a caveat section about DirectStorage on Windows 11. You don't need to be well-versed in Microsoftese to guess what that does - it's in the name! A game might want to skip a bunch of layers of syscalls and kernel logic to just get bytes directly from some block device where the data lives. Gotta be low level, gotta go fast! Well that would also skip any magic automatic decompression Windows would normally do with the transparent compression feature. You can try to use CompactGUI on those games, but the game will try to read those files it expects to be raw, finds some compressed "garbage", and say "wtf is this shit." Ultimately, this is only some low-hanging fruit for optimization, and it's great that users can claw back that disk space, but there's no substitute for game developers and publishers putting effort into game optimization beyond a bare minimum. They'll always be more motivated to optimize for ship date, and if you're lucky, FPS. In fact, in some cases, the lack of compression in game assets by default probably comes from some fearmongering about decompression slowing down the asset load pipeline and hitching FPS as you move between areas of the game. This is demonstrably false - your CPU is fast and full of cores, and the savings of reading fewer bytes off disk usually make compressed assets load faster because those disk reads are still expensive and decompression is nearly free. But big corps are heavy on a lot of things, superstition included, which is why we still see so much A* pathfinding to this day.
By the way, if you ARE on Linux like me, you actually have options for transparent compression! It just... depends on your filesystem. It's supported out of the box on both BTRFS and ZFS, and if you're on a fancy modern distro like CachyOS, you're probably using BTRFS whether you realize or not. If you're an old fogey like me and default to EXT4, well, that's not gonna work. EXT4 is rugged and sturdy and I love it to bits and pieces, but yeah, you're gonna miss some features the cool kids are using. Pick your poison, as it always goes.