It's not the merit - it's the moat (i.e. lock-in) as the linked article states. Merit in this context would mean something you can compare across different GPUs

It's not the merit - it's the moat (i.e. lock-in) as the linked article states. Merit in this context would mean something you can compare across different GPUs. For CUDA - you can't. I.e. it's a tool to force you to use Nvidia.