well zion looks amazing with the bright sun and landscape just adds to the theme and going back to vegas it justs feels dead why do they do that?

Vegas was hit by nuclear bombs (albeit less than other places) and it's in a desert. Zion was not hit at all and used to be a national park and was also more beautiful than a desert before the war. Also Dead Money, Old World Blues and Lonesome Road look worse than the Mojave in my opinion.

av done dead money dlc the place was good but got great didn't have much interactivity