What if we added mechanics like
Hunger
Thirst
Disease
Oxygen
Radiation
Bleeding
I assume this would make exploring much more perilous but also make already established cities viable options what with the immediate access to food, water, shelter and protection.
Medicines could be developed by Scientific Organizations, meanwhile players couldn't simply make a ship and fly off world. They'd need to make sure that supplies to keep them alive were present, and initiating attacks on other players much more risk reward. Trade Routes would be of more importance, food industries could be created as a serious industry what with and advance cooking system. Drugs, Alcohol and other substances would give players an opportunity to get into crime and one day becoming a pirate themselves.
So i just wanted to get my ideas out there.