Vulkan also isn't a silver bullet and support is lacking for users of older GPUs (which is a reasonable part of LFS' target market).
You need an AMD GPU that supports GCN or a pretty modern nVidia GPU. Intel AFAIK has 0 Vulkan support.
Even on my fairly recent laptop, I had to recompile my kernel to enable experimental support for the AMDPRO driver to be able to support Vulkan.
Open Source is also not a silver bullet to improvign a project.