As for ai and matrix vector performance... I mean matrices are extremely useful across many domains. The hands off language that exists today is called blas. That's fine but won't lead to the best perf on any GPU today.
SoA and AoS data layouts are not even a worthwhile point of contention. Same with shared v global mem. Today's hardware has specialized memory depending on the operation. The hardware on these processors is so specialized as to make anything but first class support for the feature be completely pointless. If you look at Nvidia code that's open source even they will special case a lot of their chips. Literally if you want the best perf you write the kernel exactly for the exact chip. That's intra vendor .. you can only imagine inter vendor