Soon, we will be in a position to engineer lifeforms much more quickly and exactly than by the process of selective breeding. To start with one may get an animal machine that performs a useful task. Already a cat will groom its coat by licking it. It seems to us to be a horrible thing to do, but cats have been doing it for millennia, and they seems to like it. In fact they like it because they are programmed to do it.
Humans have babies because they desperately want to.
Very few people see that having children is a terrible drain on one's life with the minimal reward, despite several serious and humorous treatises that have been written on the subject. Women will risk their lives in operations to correct infertility. If there is a choice between saving the mother's life or the child's at birth, some religions and cultures will demand that the mother be sacrificed. Yet if you step back and look at it coldly, you could argue that it is cruel and sick to create a being that wilfully allows itself to feel unwell for nine months and then suffer great pain to produce an offspring. Yet very few humans take this viewpoint.