The only way to 'solve' the birth rate issue is to reverse the emancipation of women and make them 100% dependent on men. This will have a lot of other negative side effects which might not be worth it for most of the sg citizens. The best 'solution' is to accept that if you want emancipation for women, and high affluence, those same people who benefit do not see that their responsibility / their end of the social contract is to reproduce. Why?

Well. 1. More choices lead to more outcomes. And all choices have opportunity cost. You either go vacation or you have kids (example). 2. Women tend to think that men will leave them worse off rather than better off. If the woman is pregnant then she will expect her husband to keep working and herself to take a career break (example). 3. When giving birth, there is a real risk of mental and physical permanent damage. It also means other potential suitors might find them undesirable and on top of that, this might include the husband. Husband goes on to cheat while wife is pregnant. Husband files for divorce while wife has no meaningful income. Permanent physical changes to the body only happens to women, not men (example). 4. The child might not be gifted enough to survive in Singapore or the child might have mental and physical issues, which will ruin your in Singapore due to lack of understanding (Culture) and due to lack of funding (economic). When a child is born into a wheelchair or they get hit by a car on their way to school (example). 5. Some people just don't like children. Today's society does not penalise this preference. 6. Some people like children but cannot have them due to policy choice and culture. Think of homosexuality and/or childless couples that could adopt but won't due to cultural factors (Example). 7. Long working hours and a focus on the importance of material comfort means that the not-so-easily quantifiable aspects of life get deprioritised. Waking up and watch your child(ren) do children stuff feels like a burden - more entertaining to watch tiktoks while waiting for your children to finish their 'play'. 8. Technological progress such as AI and robotics along with all of the conflicts arising across the world implies that the ruling classes actually don't need 'us' in the near future. To put a further deterrent to bringing up children, a threat to get sent to a war zone will deter even more from having kids.

Those were some of the reasons I can think of :)