Highly recommend Family Unfriendly [1] to understand how societal expectations and structures discourage large families. For example, people tend to feel like they have to get their kids into Ivies or whatever, which means tons of extracurriculars (which cost time and money).

Even if you have no interest in having more kids, it's an interesting look at how we can parent differently and have happier families.

1: https://www.amazon.com/Family-Unfriendly-Culture-Raising-Har...