I gave up on photo contests many years ago. The final image is my objective, and how I get to that point is not going to be dictated by some contest rules.
On top of that, many photo contests are for the benefit of those sponsoring them. Instead of having to pay photographers for the right to use their images, they charge them a fee for entering the contest and giving up their copyrights to the images. Instead of paying out fees to use your images, they take in thousands of dollars from entry fees from thousands of photographers.