So is the population of evary living creature. Allah has not said that over, say, one billion is considered overpopulated. There is plenty of space in Allah's vast earth for the world population. I understand there are more resources in some areas than others in the world. The world is not over populated.
Most people happen to live in urban areas so it appears to be over crowded.
If hoever the population was more dispersed, over crowding would not be a problem. It's not over populated or else we would not have space to build or travel by road. Nothing is in the hand of man. Really over populated. I have never understod why Arabs fell the need to get 10-12 children.