Vulkan is brand new it's going to take a while to filter down. This is the first "advanced" level tutorial I've even seen for it. And it doesn't even talk about

Vulkan is brand new it's going to take a while to filter down. This is the first "advanced" level tutorial I've even seen for it. And it doesn't even talk about rendering with Vulkan, which is way more complicated than just using OpenGL4 (and requires an advanced knowledge of OpenGL or another modern GL). Let alone doing Vulkan specific rendering techniques, which are still being explored. OpenGL is like the C std/runtime library. Vulkan is like calling the kernel functions directly without wrapping code.