Is there a way in which the monopoly is causing food to be denied to individuals? The way I see it is that any food desert either exists because it is not prof

Is there a way in which the monopoly is causing food to be denied to individuals? The way I see it is that any food desert either exists because it is not profitable or because nobody has taken the initiative to offer a profitable service. Obviously I could be wrong, but I have a hard time seeing how a megacorp is denying access to food.