The backend plays a minor role, as I repeatedly say and I am repeatedly downvoted by ignorant people. Unreal supports on MacOS not one but 3 technologies. OpenG

The backend plays a minor role, as I repeatedly say and I am repeatedly downvoted by ignorant people. Unreal supports on MacOS not one but 3 technologies. OpenGL, Vulkan and Metal and that is just for graphics. There is also CUDA, OpenCL, PhysicsX and much more that go far beyond the scope of 3d graphics. A well designed graphics engine never ties itself to a platform however popular that platform may be. Whether that platform may be a OS , a graphics API or any kind of SDK. At least Unreal is neither a game engine nor a graphics engine , its an entire ecosystem of tools , APIs. Unreal even extends C++ to facilitate for GC and some rudimentary reflective abilities. So there are a ton of things go on, from low level to very high level. Overall MacOS develpers have been very quick into embracing Metal for new projects and so did Unreal. Which is no big suprise because Metal gives access to both MacOS and iOS which is a variant/fork of MacOS.