> Don't really see anyone writing anything in SYCL though

My work involves writing software that runs on many GPU platforms at once. So far we have been going through the Kokkos route, but SYCL is looking pretty good to me recent days. There is some consolidation happening in this space (Codeplay gave up working on their own implementation and merged with Intel). It was pretty easy to setup on my Linux machine for Nvidia card. Documentation is very good and professional, unlike AMD's, which can be frankly horrible at times. And Intel has a good track record with software.

I genuinely believe if someone is going to dethrone CUDA, at this point SYCL (oneAPI) is a far more likely candidate than Rocm/HIP.