If you calm down and stop the rant, I think the main focus should be on building game engines natively on D3D12 instead of D3D9 or 10/11. Unless you have an Unreal Engine 5, for example, or Frostbite 3 build with that in mind, all the games are going to suck on D3D12.
That's not how things work. For an engine, there is no "native" thing. You're confusing game engine and renderer (render path). They are not the same thing. But they do work together to output image you see in the end. There may be things that explicitly depend on game engine support and are hard to do later, but majority isn't.