My guess is that not many of us plan to be self sufficient but with time learn learn new skills and ways of producing and making as much as they can. We swap a lot too. After just 6 months ( May-June) we slashed our food bill and since then we frequently eat meals made exclusively with our own produce (meat,veg,cider,chutneys,jams and fruit).
As for generating income - This has to be planned and location and access to a market is key. I would guess that this is a real challenge and comes with some stress - There are many plus points related to working for yourself of course but essentially generating income to live the same life style as paid work would comes with many challenges. For example it takes quite a financial investment and lots of other challenges to generate income from pigs - planning permission, H&S compliance, Vet bills, tax returns, VAT etc etc then you have to kill, butcher and manufacture, transport and finally sell the produce.
There is a third option or group.
Semie self sufficient, low expenditure pensioners. I cashed in my chips at 50 and get a small monthly pension that is more than enough for us to live on now that we produce most of our food and live a very modest lifestyle.