Number. 1: we have a food supply, we will eat when the numbers racket Crashes. Local Control of our food will Bankrupt the Banks, or lead to their end. Massive Lay-Offs, think of how much does not happen when you grow your own food.
#2: huge relief for Mother Nature, Herbicides and Pesticides would be gone. Energy demand would drop dramatically and one good thing leads to another, packaging industries would, disappear like magic.
#3: healthy air, clean water, the quality of the food, not to mention the best food for us, is what grows where we live. Gardening of course keeps our bodies active, exercise, fresh air, no stress, the white coat drug pushers would be out of business and hopefully in the Garden.
#4: if you are not convinced by now there is no point adding more benefits, of course the real benefits will be realized in the doing, until then, it just talk and imagination.
#5 gardening is great.