In case you feel like mentioning Vulkan, it doesn't come in the box, works thanks to plugging into OpenGL ICD driver model and via GPU vendors, not OS vendor, and it isn't supported in all scenarios where DirectX is.
DirectX is the official API, OpenGL and Vulkan only work because of backwards compatibility Microsoft never got rid of ICD ABI they introduced back when OpenGL in Windows NT was a thing.
That is how GPU vendor drivers expose OpenGL and Vulkan, via ICD, they aren't even supported on the Windows SDK, it is up to you to get the header files and libraries to link against the DLLs provided by the GPU vendors.
From Windows SDK point of view, OpenGL 1.1 is what is shipped in the box.
There is no support for OpenGL/Vulkan on UWP, XBox, HoloLens, Win32 sandboxes, while OpenGL/Vulkan on WSL are exposed via a DirectX driver wrapper, similar to MoltenVK.
Mac uses own API, Metal. Windows uses own API, DirectX.
OpenGL is legacy on Mac. OpenGL relies on a legacy ICD ABI on Windows.
Vulkan uses MoltenVK on Mac. Vulkan either uses legacy OpenGL ICD ABI on Windows, or relies on DirectX 12 translation layer, while WSL relies on dxgkrnl, a VM host driver that translates GL/Vulkan into DirectX as well.
macOS never really had the ability to run Windows games directly.
Either you ran a native macOS version/port of the game, or you ran a compatibility layer like Crossover, or you ran a Windows VM, or you rebooted into Windows using Boot Camp.
In case you feel like mentioning Vulkan, it doesn't come in the box, works thanks to plugging into OpenGL ICD driver model and via GPU vendors, not OS vendor, and it isn't supported in all scenarios where DirectX is.