You are right in saying that traditional practices are not a feasible solution for an expected food starved world of tomorrow. These farms do show us a world where urban cities would get self-dependent in terms of food, but there are still certain drawbacks associated with vertical farming that needs consideration. For example the diversity of plants is limited in a vertical farm and the overall architecture is way more expensive than what developing nations would really be able to afford. Moreover since most vertical farms depend on the use of black-water for irrigation, it is due to stir undue health concerns among masses.