Uh there is so much going on in this post.
I think because colonization, the development of modern science, feudalism, the "green revolution," industrialization, capitalism...and a whole bunch of other things...happened a certain way, everybody thinks the whole map of connections between these things and agriculture shows the Fundamental Way Agriculture Works, instead of just a way agriculture worked this one time.
"Subsistence farming" broadly describes a lot of traditional ways of making a living that people still follow. When you go into somebody else's culture and try to change the way people live to something you think is "better" and more "advanced," usually that ends up being something called colonizing them.
It seems a little demeaning to assume that everybody who lives the subsistence farmer life is miserable and would definitely be happier working in something industrialized or characteristic of "late stage capitalism." The Industrial Revolution really did not improve the lives of the workers it brutalized. Then and nowadays alike, I would argue that risking grievous bodily harm in the depths of mines or working oppressively long hours in factories, in very dangerous environments or with toxic substances that kill you over time, certainly isn't "better" than subsistence farming. To say that people voluntarily left farming for the mines or the factories, ignores the coercion that influenced that decision.
It's foolish to act as if we moved past "back breaking" agricultural labor with industrialization. There is less direct human labor relative to the amount of production, but human beings are still in fields doing agricultural labor under the hot sun, they are still suffering in poverty, and even where they have been replaced with machinery, somebody has to assemble the machinery and mine the metals to build it with.
If doing all your own textile production sounds so terrible, imagine doing someone else's! Obviously if the process is mechanized it is less labor-intensive, but still, a mill worker in Bangladesh made my underwear (the label says) and I wonder how much they're getting paid to make underwear all day.
Empowering smallholders is one thing, and a good goal, but the transition from subsistence farming to modern agriculture revolution didn't happen by the empowerment of smallholders. Instead it was disempowerment; nowadays most agricultural laborers don't own their land and are widely abused and mistreated by their bosses. I did some reading on it a while back and it is likely that the largest amount of human trafficking is in agricultural labor.
What's more, the sustainable and holistic practices of agriculture are being lost and replaced by destructive industrial methods.
A subsistence farmer cannot get medicine for a treatable disease? Why? What does that mean? ...Oh, you mean the company that makes the medicine won't give it to them, because they don't have money...
The practical limitations of agriculture are a totally separate thing to discuss—if a subsistence farmer's diet is poor, maybe that's because of physical limits on how much a mule can work, but if a subsistence farmer can't get medicine for a treatable disease, that's because a larger entity decided the farmer's life is worthless.
A job where your labor can be exploited, and so you're not totally worthless, isn't better by the inherent merits, it's just better because you're exploitable and can be wrung out.
