Deanna - Sourdough is a fermentation agent, a substitute for yeast in traditional bread. It is said to do a better job of breaking down gluten and making the nutrients in the wheat more readily available, but it doesn't add nutrients to the bread. The fermentation process of sourdough vs the leavening process of yeast it the reason for this difference.
Here is a very interesting (and to my mind, non-scientific) study of a small group of people alternately assigned to eat white "store bread" and sourdough bread for a week each, with the resulting changes to their bodies compared. It seemed there were few/no differences to the body from which bread was eaten. https://www.theatlantic.com/science/archive/2017/06/sourdough-versus-white-bread/529260/
So the answer appears to be that it is mostly a matter of taste.
Sue