You make a lot of grand statements there without backing anything up. If it was so convenient and cheap to cook this way, then everyone would be doing it.
I have tried and tried and tried to cook like you suggest. I end up wasting food as it goes bad before I can use it. I have a small apartment and ended up going to the grocery store every 2 days to restock. Some ingredients aren't sold in quantities appropriate for 1-2 people, so things go stale or expire before they get fully used. I wasted way more food attempting to change my food practices than I did maintaining the way I was raised.
I'm skeptical about farm shares, I don't think it scales. If it became more popular, you'd had everyone hopping in their cars every weekend and driving out to a farm. Much more efficient to load everything on 1 transport truck than to have a thousand cars on the road just for picking up produce. And in winter climates, you aren't growing anything in the ground, so this produce is being shipped in to the farm anyways, just ship it to the grocery stores. Or it's being grown indoors, which requires increased energy usage (might be less energy intensive to ship veggies in on a truck than to grow them indoors?).
Our modern food system, for all of its faults, is the only thing that works for everybody. Poor people? Disabled people? Car-less people? Dietary restrictions? All covered. Your diet and way of living works for wealthy, healthy people with time on their hands. It's not realistic at all.