x86 already has AVX accelerators that are a huge help for LLM inference speed and efficiency. It's just not enough, only the absolute weakest iGPUs are slower than AVX inference. The majority of consumer hardware would benefit from pipelining AI workloads through the GPU, especially on Apple Silicon and other ARM hardware that has borderline nonexistent SIMD support.
ARM will be ideologically opposed to expanding CPU-side SIMD, and x86 is already buckling under the weight of modern AVX (see: AVX-512 issues).