OpenCL certainly has the potential to be a universal API but support for it is surprisingly spotty given its age.

For proprietary implementations, Intel appears to have the broadest and most consistent support. Nvidia skipped OpenCL 2.x for some technical reason (IIUC). AMD is a complete mess, for some reason not bothering (!!!) to roll out ROCm support for their two most recent generations of consumer GPUs.

In open source "Linux only" land, Mesa mostly supports OpenCL 1.2 (https://mesamatrix.net/#OpenCL) at this point. So if you're targeting Linux specifically then that's something at least.

Good luck shipping an actual product using OpenCL that will "just work" across a wide variety of hardware and driver versions. POCL and CLVK are both experimental but might manage this "some day". In the mean time, resign yourself to writing Vulkan compute shaders. (Then realize that even those will only run on Apple devices via MoltenVK, and despair at the state of GPGPU standardization efforts.)

OpenCL feels pretty stagnant. Showstopping bugs staying open for years. Card support is incredibly spotty. Feature support isn't even near parity with CUDA.

This despite v3.0 being released just last year... And completely breaking the API.