If you are writing some very important function, you may write it in assembly and it will be faster than e.g. a C implementation (CPU). But how often do you do that? I think of e.g. CUDA as assembly for the GPU as you have to know about batch size, and special operations and annotations, but Futhark is like writing C or Java for the GPU (it actually compiles to CPUs as well), and it is just a much nicer experience, and I think 99.9% of all people will write faster code because GPUs are simply so complex