AVX512 was clearly a great innovation in the vectorization landscape. A far cleaner instruction set, complete and symmetric, with very interesting blend, ternlog, lane-crossing instructions and the especially interesting mask registers. Lots and lots of goodies and an eye for compiler implementation.

I feel Intel failed hard at diffusion of the ISA (why not put it everywhere, with half-perf, it'll improve later, no change in code) and also at not pushing more energy/dollars into ispc. Yeah yeah your compiler engineers are clever, but you've been doing this for 20 years and autovectorization is still ways off. Let me write code in a way that can be easily vectorized. A subset of C. Less awkward than cuda.

Now it seems AVX512 and large vector units is dying and still is too niche. Sad.