People through the history of the human species, millions of years, had children early and often as their bodies could until they either aged out or died. People have a strong biological urge to have sex that the brain is not able to override. This evolved because people who did not want sex did not have children and their genes were not passed on.
That changed in 1960 when the birth control pill was invented. This gave everyone more individual choice; people could have lots of sex but not have the responsibilities of raising many children. Factories nearly doubled their supply of workers by hiring women who were not burdened with having and raising babies, which decreased the prices they paid in the form of wages to everyone. Governments saw GDP increase without costs increasing, at least in the length of time of a human life.
The increase in individual choice comes at a hidden cost. A vast cost beyond our comprehension. We have put the continued existence of the human species in peril. Birth rates are collapsing all over the world, especially in developed nations that can afford the cost of birth control. The continuation of our species is in peril. If alien spaceships showed up over all of our major cities and destroyed them, like in the movie Independence Day, we would all fight tooth and nail to survive. But this slow invisible death of humanity is being brought on by our own selfishness.
There is also a moral cost. Humans evolved over millions of years to develop into adults through the process of raising children. Parenthood forces a person to put another person ahead of their own selfish interests from the day that baby is born until the day the parent dies. Each additional child expands that view. Parents learn an enormous amount about themselves when they have children and they put those children first. Having children should be the great maturing event of a person’s life when they go from being a self centered child to a full adult.