Comment by nicebyte
I say this because vulkan is hamstrung by being an "open API" intended to run on a very wide range of devices including mobiles. this has major repercussions, like the awkward descriptor set binding model (whereas d3d12's descriptor heaps are both easier to deal with and map better to the actual hardware that d3d12 is intended to run on, see e.g. https://www.gfxstrand.net/faith/blog/2022/08/descriptors-are...). overall d3d has the benefit of a narrower scope.
Another problem with being an open API is that (and this is my own speculation) it's easier for IHVs to collaborate with just Microsoft to move faster and hammer out the APIs for upcoming novel features like work graphs for example, vs bringing it into the public working group and "showing their cards" so to speak. This is probably why vk gets all new shiny stuff like rtrt, mesh shaders etc. only after it has been in d3d for a while.
One could argue this is all solvable by "just" adding a torrent of extensions to vulkan but it's really not clear to me what that path offers vs d3d.
The downside is that it ties them incredibly heavily to Microsoft, and makes cross-platform efforts much harder.