Don't forget the drivers. As someone who just switched from Nvidia to AMD, it is downright painful how bad AMD's implementations of Vulkan and OpenGL are. I might be getting more bang for my buck but damn do I miss not having unfixable glitches.
AMD shall own OpenCL and boost it heavily and make it a central piece for its ROCm framework as the preferred backend, in my opinion.
Apple has ditched it for metal. AMD has ditched it for ROCm which is just a AMD compiler for CUDA PTX.
OneAPI is focused on C++, and it remains to be seen if Data Parallel C++ isn't also Intel's CUDA, even if based on SYCL.
SPIR so far has hardly got any adoption to the level of PTX, regarding polyglot compute.