It’s not psychosomatic- fresh vegetables taste much better. A salad that was picked the morning of is much different.
Buying tomatoes even from wholefoods vs literally getting them freshly picked is a world of a difference. Carrots that come from Costco vs. carrots that were picked yesterday make a world of a difference. Onions look, and taste better than the ones you get in bulk. And I can go on. I've made side by side comparisons of both, and regardless of how you feel, I know personally that buying even the "organic" wholefoods variety of produce is a lot worse than freshly delivered CSA from a farm.