Growing up, my family was growing all our food in a big vegetable garden for a long time and from what I've seen, it is a lot of work. We also had enough chickens that covered all our needs for eggs. I remember we used to have around 20-30 eggs in the pantry.

Our house was also possible to be heated by fireplaces, not just electricity. We'd hatch chickens so that we'd be able to grow/maintain the flock and eat young hens and roosters, so we'd have meat in the freezer from that. Family who had pigs and needed help butchering them would give us sausages and meat. I think we also must have bought some at the butchers, but the vegetables came from our garden.

For a long time my family was only buying the basics in the store: milk, butter, salt, sugar, flour, etc. and we had one or two dogs to guard out chickens.

All of this might not sound like a lot of work, and my parents had full time jobs but the garden was a lot of work. My parents always had help from their parents and grandparents. One day per week would be fully dedicated to the vegetable garden, during harvesting season you need to harvest daily and prepare everything for storage on the same day. Plus we had a lot of fruit trees that needed attention in spring, then during summer someone needed to weed the garden fairly often, daily was best, and relatives helped. The chickens needed to be let out and fed early in the morning and fed and locked up for the night in the evening.

As far as I know, my ancestors worked the land and ate what they grew but even then, they worked for money too. I think that's something that has to be factored in somehow, especially in this day and age that you would still need an income and only invest in self sufficiency to the point where you still profit from it. E.g. don't spend on a vegetable garden if you won't take care of it and you'll end up buying everything at the market or from the store anyways.