I think the artist impression has a lot more value than a highly realistic generated face. If you see an artistic impression, you will see the facial features that were noticeable. Such as a mole, the shape of the nose, or the thickness of the eyebrows. Then you have a template that your brain uses to match those features with any face that you see. However, if I show you a highly realistic face, your brain will take a different impression. Your brain is trained on faces for thousands of years. It will try to match the face perfectly.

An artist impression tells the audience that it is inaccurate. A realistic photo tells the audience that this is _exactly_ who we are looking for.