[maxglute]

>It seems like this idea relies on a long term low wage workforce willing to live on subsistence agriculture.

It's a labour intensive, make work program that accepts the reality that there's going to be 100s of millions to billions of Africans who will be stuck in subsistence agriculture for the rest of their lives. You can incrementally improve new workforce over time as society develops, but people who get left behind generally get left behind. Ultimately, their labour is cheap, and need something to do. Maybe you can replace 1000 workers with a piece of specialized heavy machinery that's cheaper, but then you'll have 999 idle hands.