Right, but the proposal is about an API which lets web applications do shader-language stuff beyond the level of WebGL. Is this really necessary?
The new APIs (Vulkan, DX12, Metal) are mostly about performance. I can't think of any major thing that you can't implement in WebGL. But, a portable 3d API would be awesome for native apps. And, why not have that be the 3d API for the web too? Like WebGL / OpenGL ES 2.
Why on Earth (no pun intended) should Google Maps require WebGL?
Another example of people losing focus on providing actual value with the products they make.