Lack of culinary education? It's a significant driver of multigenerational health and dietary inequity. Poor people in urban areas have neither the time nor resources to cook properly, so they don't. Then their children don't learn, and the cycle gets worse. Obesity rates rise, health deteriorates, and the costs to manage that go up, making it harder and harder to break the cycle.

At least where I am, access to a variety of animals and vegetables is out of reach for those in poverty, and no one ever taught them what to do with them anyway.
So you end up with people eating mostly kraft macaroni, hot dogs and canned beans, cooked in a peeling Teflon pan and garnished with ketchup to taste. Or maybe you have money, so you mostly eat takeout.

It's why adult cooking classes are a thing that targets "entry level", like how to cook eggs (the easy ways) or cut an onion, and food banks offer classes in how to cook the food they're giving you. A potato is useless as food if you do not know how to cook a potato.