I agree with you that the falling birth rate is not just about money, but also about relationships and how people connect today. It is true that online life has made it harder for many to build long-term bonds in real life. I also think many people avoid commitment because they fear disappointment. Your point about schools becoming empty is powerful, it really shows how much society will change if this trend continues.
The trend has to continue for a while at least, because it has already started. The emptying schools is a lagging indicator.
True, it’s surprising how long the effects take to appear.