Comment by troupo
> DirectX 12 was announced by Microsoft at GDC on March 20, 2014, and was officially launched alongside Windows 10 on July 29, 2015.
> Vulkan 1.0 was released in February 2016.
What people forget is that Mantle was basically a proprietary AMD API that they wanted and developed until, well, the release of Metal in 2014 and DX 12 in 2015.
Only then did they "graciously" donated Mantle to Khronos for the development of modern APIs.
Vulkan was not just late. It suffers from the same issues as OpenGL before it: designed by committee, lackluster support from the major players.
AMD indicated from the beginning they wanted it to become the universal API.
Opening stuff up formally also takes time. So it all was going towards Vulkan in one form or another and no one was forcing MS to push DX12 NIH while this was happening.
And counter to your point, despite Mantle being "proprietary", MS directly used it to create DX12 (same as Vulkan used it), so AMD clearly didn't have any complaints about that.