[jmts]

But surely since the memory that the frame buffer is encoded into is 1D, OpenGL is really one-dimensional. /s

Sure, the frame buffer is 2D in the end - it has to be, in order to display on a standard computer monitor - but surely the fact that OpenGL is able to natively handle point data as 3D-homogeneous coordinates, and support for techniques like depth buffering out of the box counts for more than any argument that only really amounts to "after it is finished doing all its work you just have a 2D image".