What I see is that there is a tendency in more developed countries to have fewer children, and the same in the opposite direction. How is it possible that families in Niger, Mali or Burundi have so many children? considering the situation of poverty in which they find themselves. That is the same as Emmanuel Macron said a few months ago.
Even the North Koreans are reproducing faster than the South Koreans. although I noticed that he referred to the Koreans and then placed a picture of Kim Jong-Un, so I do not know what his position is regarding this.
It may just be a reproductive cycle, at some time in the past they played too fast and now it's the other way round; South Korea, for example, has twice as many inhabitants as its northern neighbor.