Lenses do have different internal flare levels as a result of their formulas, and that's going to make a difference in contrast and saturation. Lenses with fewer elements and the simplest construction will normally have less internal flare (all other things, such as coating technology, being equal).
That means prime lenses in the moderately wide to telephoto range will normally have less internal flare, thus better contrast and saturation. That's been true since forever, and still generally is.
However, most of us can't confine our shooting to just those lenses that exhibit the least internal flare. Furthermore, that's not the only reason someone would post-process their images. I agree with others that the ability to do judicial post processing will almost always result in improving any image. That's also been true since forever.
It's certainly a digital-age idea that a superior photographer should produce images that are perfect right out of the camera. In years past, no photographer--not even those who exclusively shot transparencies--would have scoffed at the photographer who did expert darkroom work.

How much "hot mouse action" do you need to do to slide the basic image sliders? 

