Even if those state group objects don't match the underlying hardware directly they still reign in the combinatorial explosion dramatically and are more robust than the GL-style state soup.
AFAIK the main problem is state which needs to be compiled into the shader on some GPUs while other GPUs only have fixed-function hardware for the same state (for instance blend state).
This is where I think Vulkan and WebGPU are chasing the wrong goal: To make draw calls faster. What's even faster, however, is making fewer draw calls and that's something graphics devs can easily do when you provide them with tools like multi-draw. Preferably multi-draw that allows multiple different buffers. Doing so will naturally reduce costly state changes with little effort.