If this would be an actual LLM-generated port, it should have been trivial to replace this Jenga tower with a direct D3D8 to Metal shim (or replace the D3D8 renderer alltogether with a Metal renderer).
Also native Vulkan support on macOS would only have removed one step in that render pipeline. Besides, I bet if Apple would offer a native Vulkan API, it wouldn't look much different than Khronos' solutions (MoltenVK or KosmicKrisp), e.g. Apple's solution would almost certainly be a shim on top of Metal, just like their GL/GLES or D3D12 implementations.
Also native Vulkan support on macOS would only have removed one step in that render pipeline. Besides, I bet if Apple would offer a native Vulkan API, it wouldn't look much different than Khronos' solutions (MoltenVK or KosmicKrisp), e.g. Apple's solution would almost certainly be a shim on top of Metal, just like their GL/GLES or D3D12 implementations.