AMD helped pay for the development of the OpenCL backend for cycles. Before that cycles gpu support was limited to CUDA. They actually hired a developer to work on it full time.
I'm surprised they don't push their ProRender renderer into the main release. I can't tell if I like it or not
I couldn't tell if that was "everything, but differently" or "most things, occasionally", or some other venn diagram of confusion, and they didn't have time to figure it out because they were busy doing actual work, so we just ended up paying some company that apparently has massive render cluster that you can rent out for basically pennies.
[1] https://www.blender.org/download/requirements/ [2] https://developer.blender.org/
[1] https://www.blender.org/download/requirements/ [2] https://docs.blender.org/manual/en/latest/render/cycles/gpu_... [3] https://developer.blender.org/T75319