Deprecation of OpenGL and OpenCL Apps built using OpenGL and OpenCL will continue to run in macOS 10.14, but these legacy technologies are deprecated in macOS 10.14. Games and graphics-intensive apps that use OpenGL should now adopt Metal. Similarly, apps that use OpenCL for computational tasks should now adopt Metal and Metal Performance Shaders.

You’re not giving history it’s due. Go back in time six years ago. What were Apple’s choices? (1) continue to live with the deficiencies of OpenGL. Remember that, over time, it had come to fail at one of its primary purposes which was to provide efficient access to GPU hardware. Further, sticking with OpenGL would be to accept the leadership of a group that had allowed its flagship standard to falter. (2) They could marshal their resources and create the better API that the Khronos Group wouldn’t/couldn’t. They really had no choice. Note that Vulkan wasn’t announced until after Metal was released. The gripes in this are should really be leveled at the Khronos group, which fumbled their stewardship of OpenGL and, with it, the chance to lead open GPU APIs.