This does however not mean that you can't use the other API's, it just means that when you are using macOS, you'll have to bring the API's with you, and that is totally possible.
In most cases, you're not using those libraries directly and using an engine instead, and most popular engines have support for the bigger API's, including Mantle, Metal, DirectX, OpenGL, Vulkan etc. You simply select the build profile of choice (or make a build that has it all) and build it to taste.