Metal is definitely used extensively in CoreAnimation, and Apple UI tends to rely on that - relatively slow (and memory hungry) rendering of layer content, whic

Metal is definitely used extensively in CoreAnimation, and Apple UI tends to rely on that - relatively slow (and memory hungry) rendering of layer content, which is then composited very smoothly and nicely in CA. They might use it for other stuff like glyph compositing (I think this is one reason they got rid of RGB subpixeling, to make it more amenable to GPU), but last I profiled it, it was still doing a lot of the pixels on CPU, as others have stated.