That's how the core has to be, like Vulkan, making the core harder allows for more control, a better foundation. Then we load up those core libraries with easy APIs that are super powerful and can do what was never thought possible.
Same for WebGPU.
So I think WASM is doing this exactly the right way as long as it stays powerful and flexible at the core.
People said this about GC but then I implemented a WASM interpreter with GC support and it wasn't very hard to do. This FX proposal would introduce... 6 more instructions I think? Not bad. Especially compared to something like the SIMD extension which feels like it's adding a million instructions.