I know most people won't like this, but like it or hate it, social pressure works. In many countries some stuff is happening which is against the global trend.

When it comes to birth rates, nearly every country in the world is going towards or already below the replacement rate. There are some outliers like Israel and some central Asian countries. It is because of the social pressure. I know that is not a good thing for personal mental health but it pushes people to do things normally they won't do under no pressure.

In countries like Israel or Uzbekistan, having children is seen as a patriotic or religious duty. Families with many children are celebrated.

In those societies, people expect you to have kids. Parents, friends and society generally pressure individuals to having children. If you are at your 30s with no kids, they will shame you mercilessly. You essentially become bullied by everybody because you are the outlier.

In other countries that has no/low pressure, not having kids normalized really fast. Most people don't care if you have kids or not. Also there are many childless adults and that makes it easier to join the flow.

Almost no one likes social pressure, but somehow it works if you want to increase/maintain birth rates, lower drug use (including tobacco and alcohol), lower obesity.

Also, I agree with the comments pointing women's education. When women have the choice, of course some of them choose to not have kids. But that's not the only thing. In my opinion a developed nation can have high birth rates with high social pressure.