Cross-platform Virtual Machines have been around for a very long time, enabling exactly the kind of thing you're talking about. So in-fact, lots of people thought about this, and built various versions of this. The browser doesn't bring anything new to the table here: it's yet another high-level abstraction layer which inevitably will incur performance penalties in a setting where performance means everything. People want to play complex, immersive games at 60 FPS with amazing graphics and textures, sounds, single/multiplayer settings, and more.
The browser was never built for modern triple-A gaming in mind, which means the APIs available for game creators will inevitably be less flexible and lag behind the more platform-native APIs we've had for 30+ years. This isn't a precedent by the way: recently developed APIs such as WebAudio & WebWorkers are just awful and don't come anywhere close to what a desktop application can do on a modern OS, and those are often considered "cutting edge". Synchronization APIs and locking primitives are only now being introduced to browsers - https://developer.mozilla.org/en-US/docs/Web/API/Web_Locks_A... - something games could easily make use of outside of the browser for the past 40+ years.
Lightweight gaming can easily take place within the browser, and perhaps this new technology can make that easier to build and use. But to build a proper heavy-weight game - you'll need much more than a browser can offer.
Completely agree that web despite being perfect for light weight and casual gaming, is not (yet) the platform for AAA games.
> - Gaming, the combination of WASM and WebGPU will be the perfect platform for cross platform game development. I could see Steam, for example, creating their own runtime.
> - Embedded electronics, simplifying the development and deployment of IoT devices.
We will finally be able to write code once and run it everywhere! I bet at least 3 billion devices will run WASM. It's a breakthrough, how come nobody came up with such great idea yet?