The system does meet the nature. We are part of the nature too. Naturally parents are protecting their daughters from having a child with a person who can’t even afford himself. How would the couple will take care of the child.
Even animals don’t bear offsprings if they do not have enough food, the right weather and protection from elements or predators. Even plants don’t bear fruit if there is not enough food or the right weather.
Similarly humans are trying to avoid having children before parents can take care of the children.
There are two things to consider. Marriage is being delayed because we increased our demands and desires. If we were living in a jungle, we would only need food, clothing and shelter to be ready to produce offsprings. But in todays society we need much more to be called ready to produce offsprings.
Secondly marriage doesn’t necessarily need to start with producing offsprings. Our culture and sometimes religion has not adjusted to the new technologies. Unlike animals humans can now marry early but they can delay producing offsprings until they are financially ready. Both male and female after marriage could continue living with their parents and continue schooling until they are ready to move together and produce children. Until that time they should be able to see each other, but stay strict about taking precautions not to produce children.
This way youth will avoid comitting the sin of adultry and enjoy Allah’s greatest gift of having sex with a spouse as soon as they are ready.