[rdsnsca]

OpenGL was deprecated, not removed from macOS.

[adrian_b]

But Apple has never implemented the final specification of OpenGL.

So even if they have kept the old OpenGL version that they had, many newer OpenGL-based applications cannot run on MacOS.

Since OpenGL is no longer evolving, it would not have been a great effort to bring the OpenGL support to the last version, and only then freeze it.