Did you even bother to look at the statistics before making such an ignorant comment? The fertility rates in countries like Taiwan, South Korea, and Singapore are much lower than in Western Europe.
That's false. Much of Europe is in the same exact demographic spiral. Europe as an overall, is in worse shape than is Asia. Most of the countries making up the bottom of the low fertility club, are in Europe.
Without immigration Europe would have already experienced a demographic collapse.
A society needs on average a fertility rate of 2.1 children born per female.
My country (Austria) has a fertility rate of 1.44, Germany even has a fertility rate of 1.38. Without immigration the fertility rate would be at 0.9 - 1.1.
This would be equal to or lower than the worst fertility rates the Russians experienced after the fall of the Soviet Union (1.1), when even life expectancy fell by 10 years on average.
Today with much better socioeconomic conditions Russias fertility rate has risen again to 1.8. That should give a clear indication of how important socioeconomic conditions are for reproduction.
Births per 1,000 people
Japan: 8.07; Singapore: 8.10; Germany: 8.42; Slovenia: 8.54; Taiwan: 8.55; Austria: 8.76; Greece: 8.80; Italy: 8.84; Bulgaria: 8.92; Hungary: 9.26; Romania: 9.27; Hong Kong: 9.38; Portugal: 9.42; Poland: 9.77; Czech: 9.79; Spain 9.88