Cooling takes less energy per BTU moved vs heating. In AC/heat pumps that's represented by SEER rating for cooling and HSPF rating for heating (heat pumps). Modern ACs have SEER ratings for 20+ and HSPF ratings for 8+. What it means is that on average, spending 1 BTU equivalent of electrical energy cools down the house by 20 BTU. Similarly for heat pump it means spending 1 BTU of electricity heats up the house by 8 BTU. Electric resistive heating is equivalent of HSPF 1.
Also in sunny climates it's easy to use solar energy for cooling making it carbon net-zero. Cold places typically burn natural gas for heating, it's much harder to make heating carbon net-zero.
You can use a heatpump for heating as well. Then not only do you get all the energy moved by the heat pump to warm a space. But you can also use the waste heat created by the heatpump for heating as well.
In a cooling scenario, all waste heat is just that, waste. But in a heating scenario, waste heat isn’t waste, it’s additional heat you can use, and reduces the total amount of energy you need to inject into the system.
Also in sunny climates it's easy to use solar energy for cooling making it carbon net-zero. Cold places typically burn natural gas for heating, it's much harder to make heating carbon net-zero.