I have a problem with the term "self sufficiency", actually. It makes it sound like it is a plausible goal to be 100% 'self sufficient', that is, to not be at all 'other-dependent'.
Unfortunately hardly anyone anywhere *ever* has been TRULY
self sufficient in that sense. I mean, the pioneers - they brought stuff along, they bought stuff trekked in from the East and Europe, they bought and traded things from others living in the area. Same thing pretty much throughout human history and across the globe. You just can't make/grow/find everything in one place, and many things are far more feasible to make/grow/find by specialists (who then trade 'em to others to supply thr specialists' daily needs) than for every family to 'roll their own'. In fact you might justifiably argue that one thing that largely distinguishes humans from other species on earth is our (largely necessary) NON self-sufficiency.
It seems to me that the rational goal is simply to not depend on others (and especially, not depend on energy-wasting earth-harming practices) for those things in life that we really COULD pretty easily do ourselves or substitute something else for.
So to me, it does make sense to grow whatever portion of your food you realistically can (which will depend on where and how you live) and try to avoid buying foods trucked in from afar. And all that.
But there is a curve of diminishing returns. A wind turbine or solar collection system probably *does* pollute less than coal-fired grid power, but you are going thru all those lead batteries... Woodsmoke (e.g. from wood heated homes) is a major cause of smog and air pollution in many places, 'free and green' tho the wood is... etcetera. And you certainly don't want to depend on self-sufficiency for medical care
Besides, there are WAY too many people on this beleaguered planet for everone to be able to go out and make like Thoreau in the forest, anyhow.
I think that in large part, the benefits that 'self sufficiency' is supposed to bring are really more a matter of just doing what we can and NOT doing what might be fun but doesn't really
need doing.
If you ask me, which of course nobody did

, what this world needs isn't self-sufficiency so much as self-RESTRAINT. No yearly vacation travel, no redecorating the house with the credit card when it gets boring, no throwing things out that could be reused, no buying things we could get secondhand, no frivolous energy-intensive hobbies (I would include water0 and far-away-nursey-grown-plants intensive gardening n this category). Like that. A way of living in which we learn to use (and be satisfied with) what is harmlessly available, not what we decide we Just Want.
THEN, sure, also grow your veggies and spin your sheep into sweaters and make pee and ashes into soap, sure, that is good too as far as it goes.
<shrug>,
Pat, whose 3 horses, all to some degree rescues, eat some hay from down the road and convert it into better pasture soil and occupy land that really oughtn't be farmed anyhow, so I think are kinda neutral in their impact on the world.