That storm already happened. It was called Unity. And since then others have joined, like Unreal.
WASM + WebGPU doesn't bring anything to the table here other than being a decade late, slower, and with fewer features. Why would anything outside of a web app touch any of it? Why would steam bother? You still have to build so, so much platform-specific stuff to make it work (input, audio, windowing, etc...), why would you do all that and then just pay a massive performance overhead to avoid compiling a whopping ~5 times?
WebGPU could potentially see a use as a middleware for things that want to use the GPU but aren't concerned all that much about performance or overhead, things like image filter effects. But there's also no shortage of existing solutions for them, either, like bgfx (as well as domain-specific offerings like halide of course)