USA is just 300 millions people. "West" depending on your definitions is about 1.5 billion people. Most of the west has cheap/free university education and good welfare. They still have problems with demography, because it's not economy that discourages people from having kids. Universally - the wealthier the society becomes - the less kids it has.
China is a great example too. After they lifted the one child policy there was no change at all. Having lots of kids was a net positive for the family’s finances in an agricultural society but in a modern service oriented society it’s a huge resource drain. Even in countries with free childcare and other policies, you’ll still have to somehow afford a 3-4 bedroom near a big city where your well paying job is and so on.
