It's mostly on us, the developers.
Vulkan is fully supported on windows.
I would say that if you want to have multi-platform support just use Vulkan.
Covers most of the platforms(especially if you include MoltenVK)[0].
Though, for games, if you want to support Xbox, that usually throws a curveball into API choice planning. As that might be more important of a target than Linux/Android/Mac/iOS(maybe even combined) for your game. So if you already have to support DX for that..
I would say that if you want to have multi-platform support just use Vulkan. Covers most of the platforms(especially if you include MoltenVK)[0].
Though, for games, if you want to support Xbox, that usually throws a curveball into API choice planning. As that might be more important of a target than Linux/Android/Mac/iOS(maybe even combined) for your game. So if you already have to support DX for that..
[0] https://www.vulkan.org/porting