Agreed, while on the face of it, population grow is a burden for people sharing limited infrastructure, it is beneficial to the economy and a valuable resource that if managed properly can produce the demographic dividend developed countries hoped they had.
The best comparison is Europe versus America. The Europeans aren’t having enough kids and are facing bleaker economic prospects while the Americans have the millennials, a young population that can keep the economy going, despite the ever higher cost of living for the average American millennial.
If the economy starts developing, people will naturally want to have less kids so they can better prepare few kids, for a more complex economy. In a simple and/or Agrarian economy, the more unskilled labor the better.
“Family planning” should not be forced into he people as it can cause unexpected side effects if done to well, as in East Asian and western nations.
On the original topic, of why the country is backwards is a general lack of adequate management and limited rule of law.
We have only partially lived up to the national Motto: “Faith, Unity, DISCIPLINE”
If we invite experts to do a root cause analysis of each and every department, IMHO, they will recommend many changes, but will our elected officials have the will to make the changes. Decades of failing to do such has allowed other economies to leapfrog us and take away our market share in industries where we had an advantage, and we may never be able to gain back that share as those other countries make technological advances to stay ahead. It may only be with greater and greater human capital costs we may be able to catch up in some areas. This is why we need our growing population.
John Nash the Nobel prize winning mathematician said that we must do what is best for ourself AND the group for the most optimal outcome. This was his equilibrium/ Game theory.