Why didn't you directly use SDL for rendering instead of OpenGL?
Was it for performance reasons?
OpenGL is deprecated on mac, and SDL use Vulkan on Window and Linux which I guess is better, performance wise than OpenGL.
Plus, Vulkan is not really "faster" than OpenGL. It just gives you a different API for programming the same graphics hardware, which in the hands of the right person can be used for writing code which is "faster".