If you have land it wouldn’t hurt to have some survival crops. Something like sunchokes (a.k.a. jerusalem artichokes, bad name because they’re not an artichoke and more like a sunflower) can grow well in a sectioned off space where they can’t spread. In an emergency the tubers can be dug up and cooked, though they’ll probably give you a lot of gas from the high incline.

Personally I love raspberries and black raspberries, which are easy to grow just don’t plant them where they can spread and run wild. It’s nice to have fresh berries!

sunchokes are fairly weedy and hard to get rid of, and don’t really produce enough calories to be worth it in a survival situation.

Also, you should grow stuff you already eat - don’t expect to grow a bunch of food that you aren’t used to cooking or eating and to enjoy it.

tbh, it might make most sense to identify what you spend the most money on and what’s easiest to grow that would replace the money you spend with time tending - usually that’s fresh herbs. Growing sage, thyme, rosemary, green onions, basil, etc. is usually fairly easy and will save a lot of money (a bundle of fresh herbs can cost like $5 for a very small amount).

Garlic is also fairly expensive per 100 g, and I found it not too hard to grow - I managed to grow enough garlic in one season in a small area on a suburban plot to not have to buy grocery store garlic for over a year.

But on the other hand, you don’t tend to buy a lot of garlic by weight, so it may or may not make sense given the amount of time it takes to garden.

People need to understand that gardening is a huge amount of labor and time spent - it’s not economical compared to working a job and buying what you need.

So, if you’re unemployed and unable to work, but able to garden, it’s unlikely to be a great way to spend your time if your concern is saving money.

If your goal is to survive a catastrophe, I think it’s delusional to expect gardening to fully provide for your calories, and the same calculus applies: your time will be better spent making yourself valuable to someone who has excess food to give away (like your local CSA farmer friend); even just volunteering on their farm is a better use of time than trying to provide for your own calories by making your small urban or suburban lawn into a food production system.

I feel like you just avoided the subject. If everyone fully relies on someone elses agriculture for all their calories then that’s putting all your eggs in one basket for an emergency. A farmer suddenly getting a thousand volunteers doesn’t increase the number of potatoes ready for harvest.

Sunchokes are a suggestion because they are perennial, store in the ground, and require no care so long as they are contained.

Something like potatoes would be great for more people if they perennial and hands off.