This is an important point that's usually under discussed. From the 70s onwards, you had multiple governments with anti-natalist policies from Malthusian fears. You had China with the one child policy for urban dwellers, in India max two children were encouraged if you want to be in polite society, feminism encouraged anti-natalist thinking in almost all countries. It was only relatively recently, maybe last 15 years, that concerns about low fertility rates started being discussed.