Zimbabwe is suffering a similar fate; when they shut down the whites’ commercial farms, they were reduced to sustenance farming - and the land feeds far less people. Instead of sending food to much of Africa, Zimbabwe now sends hungry refugees.
American Indians showed how only small populations could ever be supported with low-tech, “Earth-friendly” stewardship. Once a tribe reached a critical mass, it had to split; the land only sustains so many people per square mile. Also, you have to migrate to find your food.
Easter Island is an example of a low tech population crashing. Now that planes and modern technology visits the island life is good.