David Benatar said this quote

It is not the case that one can create new people on the assumption that if they are not pleased to have come into existence they can simply kill themselves. Once somebody has come into existence and attachments with that person have been formed, suicide can cause the kind of pain that makes the pain of childlessness mild by comparison. Somebody contemplating suicide knows (or should know) this. This places an important obstacle in the way of suicide. One’s life may be bad, but one must consider what affect ending it would have on one’s family and friends. There will be times when life has become so bad that it is unreasonable for the interests of the loved ones in having the person alive to outweigh that person’s interests in ceasing to exist. When this is true will depend in part on particular features of the person for whom continued life is a burden. Different people are able to bear different magnitudes of burden. It may even be indecent for family members to expect that person to continue living. On other occasions one’s life may be bad but not so bad as to warrant killing oneself and thereby making the lives of one’s family and friends still much worse than they already are.

~ David Benatar

This is not to offer a general recommendation of suicide. Suicide, like death from other causes, makes the lives of those who are bereaved much worse. Rushing into one’s own suicide can have profound negative impact on the lives of those close to one. Although an Epicurean may be committed to not caring about whathappens after his death, it is still the case that the bereaved suffer a harm even if the deceased does not. That suicide harms those who are thereby bereaved is part of the tragedy of coming into existence. We find ourselves in a kind of trap. We have already come into existence. To end our existence causes immense pain to those we love and for whom we care. Potential procreators would do well to consider this trap they lay when they produce offspring.

~ David Benatar

Although they will miss his presence if he dies, his condition is too burdensome to require his continued presence. In such circumstances, what is selfish is the insistence that the prospective suicide remain alive, not that he seek his own demise. The argument about selfishness can backfire in another way. Just as it is sometimes the case that those who kill themselves have accorded insufficient weight to the interests of others, so it is sometimes the case that those who do not kill themselves make this error. Consistent with what I have already said, I do not think that the interests of others are decisive. Nevertheless, there are situations in which a person's interest in continued life is negligible, because he will die soon anyway, and the quality of his life is appalling. If seeing out his days, rather than taking his own life earlier, would spell financial ruin for his family (because of the costs of his medical care), then it may well be unduly selfish not to take one's own life.

~ David Benatar

I shall not assess arguments and evidence for competing views about when human extinction will occur. We know it will occur, and this fact has a curious effect on my argument. In a strange way it makes my argument an optimistic one. Although things are now not the way they should be—there are people when there should be none—things will someday be the way they should be—there will be no people. In other words, although things are now bad, they will be better, even if they first get worse with the creation of new people. Some may wish to be spared this kind of optimism, but some optimists may take a measure of comfort in this observation.

~ David Benatar