This is the worst argument to not eat healthy. The cheap junk people are eating is completely devoid of any and all nutrition, it’s so bad it’s debatable that it’s even food.
You can get a membership to a wholesale club and buy 6lbs of chicken thighs for $18. Rice, potatoes, oatmeal, and beans are dirt cheap for carbohydrates.
People buy junk because they like the way it tastes and they’re addicted to sugar.