Crops can blight, animals can get diseases. I don't know much about hydroponics but I know that bacteria are a concern. What food source is the most reliable, the least likely to produce less food than expected?
In spring, I put a few sprouting potatoes in the compost, waited a few month and since July or so I have a huge bucket of homegrown potatoes that I have problems to use up. So very easy food source. Can recommend. There were a few pill bugs/ potato bugs who love the taste of the plants, but their damage had not much effect on the harvest in the end.
The problem with the potatoes in Ireland at the time is that they were basically a monoculture and all had the same susceptibility to the same diseases.
If you grow them as they're traditionally grown in Central and South America, you have hundreds (or thousands!) of varieties of potatoes planted in different climate zones by utilizing mountains. You have basically no risk of a total crop failure as long as it rains or you can irrigate them.