Chapel, at least, aims for both. You can write loops that it will try to compile to use SIMD instructions, or even for the GPU: https://chapel-lang.org/docs/technotes/gpu.html

the distinction matters less and less. Inside the GPU there is already plenty of locality to exploit (catches, schedulers, warps). nvlink is a switch memory access network, so that already gets you some fairly large machines with multiple kinds of locality.

throwing infiniband or IP on top is really structurally more of the same.

Chapel definitely can target a single GPU.