Black and White, no question -- everyone post processed in the darkroom, when needed or for art. But color transparencies any format, were fixed how? Those Kodachromes and Ektachromes etc? And they were dominant in many commercial venues, and still have a strong presence? That could only practically be altered when doing color separations for the web press.
That you can make something different, that you can correct problems with the environment or execution of an image, with post processing unquestionably. You can do it for your Art, or not.
Some women can apply invisible makeup and look fabulous -- for many others, it is just paint, and nearly as obvious.
PP is just a tool like the camera- some use one or the other well, a few both.