Renting and being self sufficent

I often read and or hear people say "Oh but I rent so I can't do that whole self sufficency thing" and I have to say this bugs me a lot sometimes beyond words. I have yet to come accross a landlord or real estate agent that has no problems with me as a tenant using any empty space in the garden to plant what ever I please. As long as I am maintaining the yard to a good standard they don't really care. Besides self sufficency is not just about gardens there is so much more to it and what ever you choose to do to lessen your impact on consumer driven living your making a positive impact. To me self sufficency is all about just that doing what you can to not rely on others for your survival.
I have gone and asked past real estate agents if I can add garden beds or no dig garden beds and every time I have had a yes. In my adult life I have restarted my garden at every home I have lived in and that has been a total of sixteen times.
It can be as small as one of my efforts in an apartment in Kings Cross that was so small that the entire apartment could fit in my current lounge room with space to spare now.At that apartment I had herbs in pots on the window sills of my lounge/bedroom/kitchen and of the bathroom. I did have up on the roof some fruit boxes with vegies in them till I went away for a long w/e and they died in the summer heat.
Then it could be as much as we currently have. When we moved in the backyard would have made any green thumb enthusiast collapse to their knees and wonder what sort of person lets this happen to a yard. All the garden beds were filled with grass and weeds along with the manure of the previous tenants 3 very large dogs. It took us over two months of hard work to get the entire areas cleared of any sign of the previous nightmare.  We have only on one small area measuring aprox. 3m by 5m gone outside garden beds for everything in this bed there has been a rotation of potatoes, beans, tomatoes, broccoli and now chard, beets and soon parsnip will be added along with broad beans. We have kept our 6 hens and one rooster in an area previously barren of life within what should have been a garden bed. All other areas of the garden have some sort of vegetable or herb growing in them
Yes we are lucky to have a large area to use but that is pure luck and us being able to negotiate around the large bushes and trees to achieve what we want.
You could use old food tins to grow miniture plants like tiny toms and herbs.
So I guess what I am trying to say just because you rent does not mean you can't be self sufficent to some degree.