There's a point to make which is that most people don't probably have problems writing Vulkan code, but shaders instead (that's unless you already know OpenGL). For Vulkan you have many good bindings already in different languages, but then you get into actually writing shaders which requires completely different programming mindset -- everything runs in parallel by default. All your algorithms have to be divide and conquer, so say bye bye to imperative style accumulators. The concepts might be hard to grasp unless you know your way around functional and array programming languages.