[exDM69]

> OpenGL is "learnable" by someone in the process of learning.

If this is the case, it's only because there is much more material and tutorials written. Not because OpenGL is simpler or better.

I know because I watch noobs stumble with OpenGL all the time over at ##opengl in freenode. It usually takes them a week or two to get a triangle on screen, and they're super confused about semi-opaque concepts such as "vertex array objects" (they're well documented in the OpenGL wiki, but reading documentation seems to be out of fashion).

It would certainly help (them) if they had a good knowledge about 3d graphics in general before stumbling into OpenGL. But if they had, they'd be able to do it using Vulkan or Metal with no great difficulty. OpenGL isn't at all better here.