makes you safe
As an individual, if you think something is harmful, ground rent lets you leave for a better job, or even a better government.
As a society, if something makes your neighbourhood or country less attractive, it will show up in ground rent: you have the data and science to prove it.
As a planet, if something huge happens - an approaching asteroid, or super volcano perhaps - ground rent's vastly stronger economy gives us the wealth to do whatever we need.
Ground rent is a matter of survival.