I'm not sure that anyone, anywhere can create "fantastic" food out of "subpar" ingredients. I do think much of the world does create fantastic dishes out of what are, in their particular places, simple or inexpensive ingredients.
I definitely have to watch pennies but I make very good food out of inexpensive ingredients. I am very lucky, though. If there is something that could be described as the opposite of a food desert, I am living in it. Good, inexpensive produce, grains and legumes at a variety of ethnic markets. Virtually any herb, spice, or condiment that anyone could want within a walk or short bus ride away. I can't afford organic but I can afford fresh. I find that produce in fruit markets and ethnic markets is usually much less expensive and much higher quality than that in supermarkets. I'm lucky to live in an area with both. There are people in vast swathes of this city that do not have this kind of abundance available to them. There are many neighborhoods on the south and west sides where the most --and sometimes only--accessible food purveyors are dollar stores.