People who don't raise children often contribute by financially assisting relatives who do have children. Also, they often take a more active role in caring for their aging parents than those who are busy raising children of their own.
Also, not all parents are good parents. And the children of bad parents are more likely mess up their children as their parents messed them up. In that case, it's better that they not become parents at all.
Raising children is not the only way to contribute to society.
Without raising children no society can survive. It is more important than economy, culture or politics.