That was the question I asked myself, when I thought about taking on home canning. Here are a few of the answers.
Although one might think that since we live in the tropics we can just stick our hands out the window and grab a banana or mango any day of the year - well that's not quite the case. We have seasons here (rainy and dry), and seasonal foods as well. We are able to benefit by purchasing these foods when the price is best, and storing them for other times of the year. Canning is a super way to do this.
Also, we have a limited amount of freezer space. Currently, we're just running the little freezer on top of our refrigerator, because we don't have enough power to run the chest freezer. By canning some vegetables and meats, we have some extra food stored beyond what our freezer can hold. Plus, there is always the possibility of losing power, and thereby losing all the frozen food. I'd love to be able to say "that can't happen to us, since we're using solar energy" - but it only took a couple of lightning strikes to teach me that we're vulnerable to power outages, too.
We've experienced few major disasters in Honduras since my family has lived here (nothing even close to the significance of Hurricane Mitch). Even so, there have been times when bridges have washed out, and landslides have closed roads - it actually happens quite frequently here in the mountains. Honduras doesn't have lots of roads. If the major arteries are shut, food and fuel and other supplies just can't get through. The unions use this fact to their advantage, by holding their strikes on the major roads. Usually they get the attention of the government very quickly, as traffic rapidly piles up in both directions. Allen and several of the children were caught in a huelga (a strike blocking a road) a few years ago, and they were stuck in traffic for a couple of days! So, I say all that to make a case for having some extra food around the place - enough so that our family won't be in trouble if we can't get to where food is being sold, or if the food can't get to our part of the country. Last year, during the curfews related to the political situation - which sometimes lasted for several days without a break - we were relieved to have some stored foods in our pantry!
One final advantage to canning has been the ability to create "convenience foods." We don't have many options for quick and easy meal preparation available to us here, and the options we have are generally imported - and therefore expensive - items. The ability to pre-cook a large amount of meat (or beans, or veggies) and have that item ready to heat-and-serve is an unparalleled luxury for us!
So far, we've successfully canned chopped chicken, ground chicken, green beans, red beans, orange slices, and tomatoes. We're quite pleased with the results!