Intel also had KNC instruction set (AVX512-like) on Xeon Phi (these CPUs available on PCI cards). They abandoned it in favour of good old x86. One of important factors was the difficulties related to tooling, especially necessity of cross-compilation.
And speaking of x64...
> It's why x86 won. Do you really think the world has changed radically?
No, x86 is loosing to x64. And at some point another instruction set will supplant x64.