Some people should not reproduce. There should be requirements for people to have children, but it will never happen. It will never happen because the laws were wrote and are written by the elite.
The rich elite business owners need you to keep pumping out babies in order to keep their factories running. Your children will likely be the elites worker bees. Most poor to lower income people work at the bottom of major corporations or other businesses. The more humans (aka slaves) there are, the less power slaves have. You are easily replaceable. There are millions of other slaves willing and ready to take your job if you are a disobedient slave.
Billionaires and other rich people do not want to be at the bottom working for low pay. If there are fewer humans, they will lose their power. They want to keep the world exactly how it is. Them at the top and you at the bottom serving them.