Exactly, even if you have closed loop geothermal heat pumps (which more efficiently exchanges heat from the thermal mass of the ground and the refrigerant pumpe

Exactly, even if you have closed loop geothermal heat pumps (which more efficiently exchanges heat from the thermal mass of the ground and the refrigerant pumped through a heat exchanger) you are still limited in the amount of heat the refrigerant can exhaust into the ground before you've heated up the ground where it's not possible. And vice-versa in winter where you can freeze t he ground solid by doing the opposite. Still a good idea, but has scale issues especially for high-density areas.