> your options are basically having a GLES renderer that you can restrict to WebGL2 (so no compute shaders, etc. and other things that make desktop OpenGL acceptable for writing a modern renderer) or having to abstract over Vulkan/WebGPU yourself

I don't understand this complaint. What's worse about using WebGPU over using GLES? Seems like a strict improvement. You can use WebGPU anywhere, you're not required to "abstract" over Vulkan. If you're talking about using it outside of the web, you just choose wgpu or Dawn as your implementation, it's the same API and even the same implementation as you'd get in a browser.