If mobile support is important, the Vulkan 1.0 feature set is basically all you can hope for unfortunately, with or without WebGPU inbetween.
For WebGPU it was the right decision to select the base feature set for the biggest possible reach. Desktop-GPU extensions can still be added on top when the need arises.
Just like it happened with WebGL, I bet WebGPU will stay at 1.0, and maybe around 2032 we might eventually get WebGPU 2.0 with the native capabilites available 2023.
