Google's native implementation of WebGPU, Dawn, has DirectX/Metal/Vulkan backends, as well as fallback to OpenGL when not available. So it's already ubiquitous

Google's native implementation of WebGPU, Dawn, has DirectX/Metal/Vulkan backends, as well as fallback to OpenGL when not available. So it's already ubiquitous today, you just can't use it in the browser (yet)