Performance of the game is much more important than download time

Its really common to sacrifice disk space for runtime perf

For gamers 100GB is not a big deal, CoD is like 200GB and its extremely popular

I disagree with your assertion that games running in a browser are not performant enough. WebAssembly being ~45% slower than native sounds scary, sure, but that's basically what you can expect from using any non-native language anyway. So if Unity is performant enough where all C# code has similar overhead then it should all be fine.

Plus not all games are AAA.

Unity doesn't use C# for everything. Notably the game engine itself is not C# but C++. C# is essentially just the scripting language.

You're also ignoring the overhead of WASM -> WebGPU -> native graphics API, not to mention how much harder it is to develop and debug that platform than it is a native one.

Unity is just an example. And depending on the game you may actually be doing heavy work in "just the scripting language" instead of the engine. XNA, MonoGame, Love2D, etc. are all frameworks rather than game engines so they're absolutely doing typical engine work in the scripting language, if you need a different example.

> You're also ignoring the overhead of WASM -> WebGPU -> native graphics API

Wine -> DXVK -> native graphics API works great for many people. I can't imagine it having significantly worse performance characteristics, especially when WebGPU is closer to the native graphics API than DirectX on Linux is.

> not to mention how much harder it is to develop and debug that platform than it is a native one.

But why? You still have access to a debugger.