There is raising plants and animals and there is breeding plants and animals.
Survival blogs, shows like Doomsday Preppers, etc. all stress having to raise your own food. Well let me tell you the homestead movement goes back much farther in time than the modern survivalist movement. We were basically people who raised our own food for a number of reasons. In my case my family had a number of food allergies. Food allergies are much easier to deal with now than in the past. You have allergens now listed on packages of food. Back in the old days this was not the case so you learned to cook from scratch. This led to raising animals to know what they were feed. It led to raising a garden and canning to know what we were eating. Along the way we went from raising to breeding. Now let me explain the difference. When we first started out, we purchased plants and animals. These were raised then turned into food and new plants and animals purchased next year. At some point we keep seeds and poultry. We started hatching eggs and planting the seeds we saved. What we quickly learned was you cannot always tell the genetics of what you buy. We went through many strains of poultry eliminating those with health problems and those that were not adapted to our climate. In the end we got down to a line of buckeye chickens, royal palm turkey and muscovy ducks. These flocks have to be large enough to allow flock breeding. It was a long process to get these lines that can sustain themselves. And it takes work to keep these lines healthy.
Now the same goes for plants. First we had to learn what diseases and insects were in our area along with the times of year they are a problem. Next we had to select plants that would work in our climate. Creating the garden was trial and error in some ways because we limited the use of herbicides and pesticides. As we found plants that truly worked we had to see if we could save seed. Many of the ones that worked were hybrids. Saving those seeds would not produce the parent plants in many cases. So we identified non-hybrid where we could. Then came the work of pollinating and collecting seed. We had to isolate the plants if we were growing several varieties. Otherwise you just produce hybrids. So we had to master that and then proper harvesting and storage of seeds. We also did some work with hosta and daylily at that time. In that case we were creating hybrids to obtain a desired trait. We had to learn more about genetics and things like freezing pollen to use a year later.
So after many years we developed the skills and knowledge to be breeders.
Most people who buy seed banks of plants for emergency food or plan to raise animals for survival food are at best raisers. Before you spend your scarce resources on some plan to raise your own food, decide if you are going to be a raiser or a breeder. If you are looking for a sustainable population in your environment than you will likely need to be a breeder. So be prepared to put in the time and effort to develop your lines of plants and animals.