alt Hacker NewsI 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.