> They only have to write drivers for their own hardware, and for their own GUI library.
They’ve always had limited processor and GPU options though (relative to MS where Windows had to support an insane amount of options), so wouldn’t they have optimized for what they knew would be in the case?
They'd still be constrained by Intel/nVidia's expected API design and almost certainly some key code from them as well. With apple controlling the hardware too, they can make the interface work however they want. That introduces the possibility of making some radical simplifications or optimizations.
They’ve always had limited processor and GPU options though (relative to MS where Windows had to support an insane amount of options), so wouldn’t they have optimized for what they knew would be in the case?