Not to mention kids require an investment of time and care that a lot of people just don't want to make. Given the actual ability to not have kids, some couples choose not to. And it's good that they don't have to, I mean, how many shitty, abusive parents were there in the past before birth control? People in rich countries are making the mature choice not to have children. People in poor countries would also make that choice, if they had the same access to reproductive care.