They wouldn't be economical. Smaller buildings and homes are fine with air-source heat pumps, likely with a bit of induction heat for the very coldest day. And air source are easy to retrofit into any building with existing thermal heat conduction solutions such as air vents or hot water radiators.

I priced geothermal heat pumps and water source heat pumps vs air source a couple of years ago. The capital cost of geothermal is much higher, and retrofitting is much more expensive. For new districts and new large buildings, it would make sense for government incentives to be in place, but these developments are rarer than you would think, and harder to influence in many ways.