There is this question that kind of worries me. The "accepted" answer is the answer written by the author of the article which caused in the first place the confusion about "Opengl being a 2d api" ...
I think that the accepted answer is really misleading and close to be plainly wrong. What really bugs me up is that the author of the article is self answering a question that initially caused confusion. Many people already answered with great counter arguments but the user persist to believe that he is right.
I plan to add a new answer to this question to give some more arguments against the idea that opengl is a 2d API.
I believe that even if this question is based on facts, it could be closed with "mainly opinion based" because someone cannot accept to be wrong and ignores all the arguments that other users are giving out.