[D] How valuable is learning CUDA/ C++?

Everyone is currently trying to make AI implementations fast/efficient (because more efficient -> less money spent on compute).

For instance, flash attention 2 is implemented in CUDA. Llama.cpp is C++

Is PyTorch enough? or is there an advantage learning CUDA/C++ in this market, especially for LLMs?

And if CUDA is useful in some cases, what are those cases?

attention compute cpp cuda flash instance llama llms machinelearning market money pytorch