That's the difference right here. If you are in business of making engine then yes you can benefit basing your engine on something like Vulcan. To me: I am not exactly doing games/engines. I do use hardware accelerated graphics for some other type of development. OGL/DirectX are already a nuisance enough for me (just a friggin too that I want to use and forget). Having to go even lower level will not make me any happy at all. Well that is unless I find suitable rendering library. Hopefully some candidates are available now, just have to find time to evaluate.