Up until a few decades ago, women did not have a nearly foolproof way of preventing pregnancy while still being able to have dec. As well as having the power (financial independence) to say no to anyone pressuring them into getting pregnant. So now, the fertility rate will more accurately reflect a woman’s desire to get pregnant (at a certain age, at a certain income/wealth, given a certain set of possible partners, given a certain number of other children they already have, in a certain culture/time).

The caveats in the parenthesis are almost unnecessary though, since we are seeing declines in birthrate across all incomes/wealth levels around the world. I think we will see very, very few women choosing to have more than 3 kids, or even 3 kids. I actually only know of 1 couple with 3 kids, everyone else has 0, 1, or 2, and I am in mid 30s.

Decline in birthrate is a good thing, especially if we combine it with the reduction in mortality, and hopefully slowing aging and reversal of aging.