I'm super frustrated by the state of 3D on web right now as an app developer. I wish we just had Vulkan on the web ...

Right now 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, which are similar but different enough to increase your code complexity considerably.

There's abstractions like wgpu and bgfx you can commit to, and of course you can just use game engine middleware and have it all done for you, but overall things fall short of just being able to "write once, run anywhere" a renderer, sadly.