The Vulkan situation on Apple is incredibly funny, especially once you look at the landscape of gaming. There's games out there (I believe Final Fantasy XIV is like this) where the official Mac client runs in wine, using a DirectX -> Vulkan translation layer, on top of a Vulkan -> Metal translation layer.
One can go that way, or use one of the middleware engines that has support for Metal for several years now.
There is no Vulkan on game consoles, those little devices HN keeps forgeting about.
Yes, the Switch supports Vulkan alongside OpenGL 4.6, but if one wants the full power of the games console, the name of the game is NVN.
As for Apple, all relevant middleware has support for Metal.
WebGPU is basically a middleware for those that just want to use graphics, not all of unity, unreal, etc...