Have you wonder why Japanese population is decreasing with less marriage rate, in spite of the government's attempts to arrange a variety of legal measures and tax benefits to incentivize married couples to have kids?
Many unmarried people say it's because marriage costs money and it has turned into a risk, rather than security. I do not think it is the reason because apparently living as a family unit is more cost effective and more advantageous in terms of tax benefits. and I think that the government is thinking the same way, which is why their attempts have all been failing. It's not really about money because poorer countries in general enjoy higher marriage and birth rates.
I think the real reason is because the traditional Japanese family values that we had been embracing have eroded. Nobody stresses the importance of family ties, at home, at school, and in the media.
Japan used to boast of its strong family structure. It was common that 3 generations live in one house. Now that family structure went almost extinct. Then there appears "nuclear families" in which 2 generations live in a house. This style is also going out of fashion, and 1 generation households are emerging. At this rate, this model is also going to die out, and what will be left with us will be 0 generation household.
Then what is the solution to achieve a sustainable demography? I hear ideas like accepting immigrants or develop robots that can tend old people, but I think those are just measures, not the solution.
Look at Europe. They accepted tons of unskilled immigrants, just to make their population curve look auspicious. There measure resulted in cultural collisions and high crime rates. Servant robots? They will not bring the population statistics back to a sustainable shape.
People are just looking at a tree with pretty flowers, but they are not seen the entire forest under wildfire.