isnt overpopulation the greatest problem facing the world today?

Yes.  Over-population is the elephant in the room.  Even California is challenged with having way more people/agriculture than they have water resources.

We can still make more space and food in the sea and underground.

To do that, people should be able to be more aggressive and constructive.

Systems allow for more detailed and automated management.

That false theory has been around for 200 years.  "Thomas Malthus  (1766–1834) , English economist and demographer who is best known for his theory that population growth will always tend to outrun the food supply and that betterment of humankind is impossible without stern limits on reproduction. This thinking is commonly referred to as Malthusianism."

No the rapidly diminishing supply of fresh water.