Why should we bring up more children?

I read an article recently that highlighted the dawn of the New Girl Order made up of Single Young Female (SYF). They are appearing everywhere on Earth from affluent parts of Asia (Japan, Singapore and Hong Kong) to Western Europe (Spain, Italy and UK) they are spreading. The birthrate for Hong Kong is at record low 0.98; less than one child per woman. So 'highly' educated and affluent nations' rates of growth are dimishing and those countries in need of more education and higher literacy rates are increasing quickly. In less than 50 years, the world will be a different place. If education makes the world a better place, we better start educating quickly.

The article says "SYF are having too much fun". It also says because most SYF do not want to be "housewives" of men in their societies. Understandable. These are two reasons amongst many factors covered in the article adding to the trend of more SYF and later marriage - higher education, career development, better lifestyles.

But something is missing. It did not mention whether or not there is a need (or want) for SYF to bring up children at all.

Are there good reasons for having children? Not because they're cute, not because "you have to", not because "aww everyone else has them too", not because "I'm married". Could one reason be: there is a need and responsibility to bring up another human being? A responsibility to educate, to give life, to let them have choice, to let them change the world in their own way?

Yes, adoption works too because there are a lot of children who need good families and the world's population is exploding. But there haven't been a lot of statistics about SFYs adopting mass numbers of children around the world... so I wonder.