[dman]

I would much prefer hardware vendor supplied drivers since they have an active interest in adding support for newer versions of graphics apis. OS vendors have proven to have a very poor track record supporting newer versions of graphics apis that they did not create themselves. (Microsoft support for OpenGL on Windows and OpenGL/Vulkan support on Mac). Calling driver vendors "unofficial" seems a bit backwards to me.

[Rusky]

You're leaving out the "official" counterpart- Direct3D drivers. Microsoft and hardware vendors both have an active interest in adding support for new versions there.

[vetinari]

Microsoft has interest for pushing new versions only in new OS releases and uses that to push these new OS releases - see DirectX since 10.

GPU vendors do not care, they will give you API to their hardware for any OS version that moves their wares. That's why I would trust more GPU vendors than OS vendor.