Frankly, there is a larger understanding among young people that it’s irresponsible to have a child unless you’re financially stable with a good space for a home. Turns out that _most_ young people (outside of the software biz, of course!) don’t make enough money to support themselves plus a kid, plus a home with space good for raising kids. And they don’t feel outward pressure from their parents or religion to have a kid nearly as much as they used to.
And beyond that, poor mental health and knowledge of what kids can be like also means young people just don’t feel ready to raise a kid for quite a while.
These factors won’t go away without serious changes in how our economic system works.
I would also ask if it really matters that the birth to death ratio is more than one. One seems like a good baseline to maintain.