The biggest advantage of Vulkan is that there are games relying on Vulkan, which means GPU drivers have to play nice with it. My impression is that OpenCL is borderline unsupported. In fact, there is an effort to reimplement OpenCL on top of Vulkan because the drivers are just that shit.
i would imagine nvidia to not want their moat with CUDA be uprooted, and so their vulkan support might get gimped in some ways (that does not affect games). At least, that is what the cynic in me would predict.
Nvidia have actually been putting a fair amount of work into their OpenCL drivers in the past few years and have a pretty decent implementation, I have a feeling that opencl is more widely used in the embedded space and they were kicked into gear
AMD, very recently have also been putting a bit more work into it, though their drivers are still the worst, and still way worse than their pre-rocm drivers
I work in VFX and I see that OpenCL has been used quite a bit in DCCs such as SideFX Houdini (which uses it extensively) and Foundry Nuke which uses it a bit too. Most of the GPUs are NVIDIA but there's some AMD too, and it's ability to fall back to the Intel (CPU w/vector instructions) host when running of the renderfarm, is absolutely critical as farm nodes generally tend not to have GPUs (most of ours don't even have X installed! So no hardware-accelerated OpenGL OR OpenCL is possible at all!)
Also one of my favourite non-VFX projects: 'Gollygang Ready' uses it to accelerate reaction-diffusion simulations.
I (perhaps naively) thought that OpenCL would still be a thing in a post-vulcan world.. SideFX are working on a new viewport using it.. I guess they solve different problems so can still coexist?
