Microsoft don't really get to dictate it beyond their own games. Vulkan already exists, it's on developers to use it and through use it will be improved. Nvidia is a problem, right now you really want an AMD card for Linux and Nvidia are not rushing to support it. Linux is forever maturing, which is why it will struggle to ever see wide-spread use, unless major players suddenly start support for it, but why would they, when the market share isn't worth it... and on and on it goes.