1) The low level thing MS has is DirectX 12. I saw some benchmarks across multiple graphics cards that showed it was slower than Vulkan, but I can't seem to find it now... so its unclear to me if it is or isn't slower.
2) I think the people here would rather it be developed by an independent group like Khronos Group. For example, Apple created OpenCL as an open standard too and then abandoned it.
On one, ok. I haven't followed DirectX too closely. I knew 12 was designed to match modern GPUs much closer but I didn't know if that was sort of 'medium' between DX 11 and Vulcan, there being something even lower from MS.
And does it make security assurances making it suitable to expose to the web?
I know a bit about DirectX and OpenGL, and I wouldn't expose a direct interface to either of them on the web. Does Vulcan make security and isolation assurances? If not then it is useless.
Obviously there has to be a ground up rethink with security in mind. The standard won't be the same API, just like WebGL isn't the same as OpenGL. It's just, where it's possible to, you use the same API. The point is why not start with a starting point you can use on potentially every platform?
There's no way Apple would ever allow Metal proper to be ported to PlayStation or Windows, so you're limiting yourself to at best two platform coverage targeting this new standard. Vulcan will, hopefully, work on every platform. At least subsets of it, with shims. No way Metal ever gets there.
2) Apple is proposing an open standard here, they're not making WebMetal
3) Why do you think Apple's proposal doesn't?