When I was stationed in Germany, the birth rate was below the replacement level , less than 2 kids per family, because most Germans felt that they couldn't afford children due to the high cost of living and taxes. I might point out that everything was expensive partially due to the value added tax (VAT). The dims have suggested that here.
I was stationed in Berlin from 1974 to 1977 as a 20 something young man looking for female companionship and finding few in my age group. At the time I put it down to the fact that West Berlin was isolated in East Germany surrounded by the Wall. We soldiers called West Berlin, “The St. Petersburg (Florida) of Germany.” A large scale retirement home.
I can see now in retrospect that the problem was common to Europe in general.