Earlier quoted context omitted.
Are you suggesting that humanity will die out so long as only willing, intentional parents have children? That is an interesting thesis and conclusion to come to (total fertility rate = 0 vs somewhere between 0 and 2.1 [replacement rate]). We should empower people who want children to succeed, and empower people who don't want children to never have them. What happens after that, we can solve for.
I think many people have a misunderstanding of what lower fertility means. Imagine a country has a fertility rate of 1. It doesn't seem that bad because it's pretty close to replacement. But fertility is an exponential system. So a fertility rate of means that each following generation (~20 years) will be half as large as the one that came before it (the formula is simply a ratio of fertility_rate/2). So you won't se…
What will end up happening is that some groups will maintain replacement fertility levels or higher, and some groups won't, but we'll trend towards an equilibrium, or flop between too little fertility and too much fertility. Either way we won't go extinct unless we explicitly kill each other.