GLES2, GL3 and GL4 are the "clean parts" only, OpenGL 1.x features have been removed. But the API is still a mess and has all the design mistakes dating back to

GLES2, GL3 and GL4 are the "clean parts" only, OpenGL 1.x features have been removed. But the API is still a mess and has all the design mistakes dating back to 1992.