In DirectX 11 and classic DirectX 12, the CPU had to record every single GPU task in a massive linear list. If a game needed to calculate shadows, then physics, then lighting, the CPU had to sit there, line by line, building that list.
We have reached a point where CPUs aren't getting much faster; they are just getting more cores. Work Graphs finally admit that the GPU is the star of the show. By letting the GPU manage itself, Microsoft has effectively removed the traffic cop from the intersection. latest directx