IIRC air conditioning is generally less demanding because you’re ‘only’ trying to drop the temp by ~30F to get back into the 70s on a hot 100F day, whereas for heat you’re trying to increase by a much larger 50-70F on a cold 0-20F day. I’m sure wishing the house was better insulated today (Austin).
Air conditioning can also be more than 100% efficient (from the point of view of the heat in the room), because it's moving heat from inside to outside. If you're using electricity to heat your house, it's only 100% efficient because each kw is being dumped directly into the air. This is why heat pumps are so great, they're basically just ACs in reverse, so for 1 kwh of electricity, you'll get more than 1 kwh of heat in the air of your house.
The insulation thing is weird because better insulation saves you in the summer too. I guess it's just the construction fixed cost. Electric heat seems like a weird compromise though considering the gulf of Mexico..
Electric heat doesn't need any duct system though, which is nice. Also, no chimney to worry about. For places with low-co2 footprint electricity, it makes a lot of sense.
Granted, down in TX central AC is a lot more important than worrying about heat for a once-every-30-years cold situation.
As an FYI I’ve really enjoyed (Austin-based) Matt Risinger’s home building channel on YouTube [1] recently. He often discusses efficient building trends and materials. You think about your R-value much harder when it’s 9°F outside...
[1] https://youtu.be/Ro3Tg9-PqFc
I think the problem is that homes are also designed to cool, efficiently, which is why many a/c and heater units are in the attic with vents in the ceiling.
This means that they tend to heat homes more inefficiently than in places that are used to very cold weather.