I peeked at the source code of the shaders, it looks like it is metal for the web.
I don't get how a closed API like metal could be the future of an open internet. Yet it can start a discussion.
"We expect the discussions around the shading language to be one of the most fun parts of the standardization process, and look forward to hearing community opinions.
For our WebGPU prototype, we decided to defer the issue and just accept an existing language for now. Since we were building on Apple platforms we picked the Metal Shading Language."
Apple had their own 3D API in the old days, Quickdraw 3D.
They only played nice with OpenGL, because of NeXT acquisition, NeXTSTEP had Renderman and OpenGL, and they needed to bring developers into their eco-system to avoid closing doors.
Now the bank is full and with graphics middleware, a 3D API is just another interface implementation for the scene graph rendering calls, that are actually used.
Metal is already supported by the majority of engines that matter in the industry, with Qt in the process of adopting configurable backends as well.