"Frank Arthur" wrote

Why would anyone not enhance (retouch) an image to improve it if it
were possible to do so.

This depends upon the purpose of the image. For instance, the retouching of
news photographs can be of serious concern if it alters a relatively
straightfoward depiction of reality. (This is a legal minefield so my words
are just a rough description.) And then there are photos such as in
holiday brochures where retouching can give a false impression of the
resort. (Although in this case it is unusual for them not to be retouched).
There are countless other examples.

Roger