I think I have hinted about the population explosion in my previous post. It is so much that people cannot survive on agriculture alone anymore. How people without land can survive?
During the Indus civilization, the population in the Pakistan area was probably less than 1/ 1000th of today.
Everyone was holding agricultural lands, everyone lived mostly in the rural areas and very few needed to work other than tilting their parental lands. Lands were abundant and almost all were left without cultivation.
Now, with 220 million people in Pakistan, not everyone holds farmlands. During Indus, people cultivated cow dung as fertilizer. But, with the population explosion, cow dung has been replaced by chemical fertilizers like Urea, Potash, and others in the 21st century. A unit of land has to produce more.
These are expensive chemicals. However, their production, transportation, and distribution created jobs. I want to emphasize the production of any other factory goods creates jobs. So, a country has to keep on building manufacturing factories. If it does not want to perish, it can force people to reduce the population.
However, our leaders in developing countries like BD, SL, and Pakistan love to import industrial goods instead of going through the painful process of building factories.
The result is the bankruptcy of SL and the future bankruptcy of BD and Pakistan.