Why are there not enough births?

Sometimes there's only one candidate for a job and that person demands more than minimum wage. It hurts profit.

Births in western Europe are less than the amount needed to keep the population stable: the population of those countries is long term decreasing. (but there is often immigration to make up for it)

I think the US is about even, or slightly positive. But then the US has a lot less people than Europe on a per land area measure.