The nice thing is that for GPUs you're rarely writing directly against the metal but instead pseudocode lowered by the driver; the driver could know to just lower it this way. On an NVidia GPU they control the whole stack and don't need to get a further ecosystem going there. Possibly the same for Apple.

Apple is such a vertical stack, I'm not sure how to generalize from that. Certainly the same was true on IBM mainframes. And, when I wrote open source, I could probably have written abstraction more broadly.