I think Rust GPU is built on top of Vulkan + SPIR-V as their main foundation, not on top of CUDA or ROCm.
What I meant more is the language of writing GPU programs themselves, not necessarily the machinery right below it. Vulkan is good to advance for that.
I.e. CUDA and ROCm focus on C++ dialect as GPU language. Rust GPU does that with Rust and also relies on Vulkan without tying it to any specific GPU type.
The article mentions Triton for this purpose. I don’t think you will get maxed out performance on the hardware though because abstraction layers won’t let you access the fastest possible path.