Notice how you switch from "more energy efficient than most..." when talking about heating, but then switch to "is not always the most efficient..." when talking about cooling.

Both are active temperature control, and both are much more efficient than previous forms of heating and cooling.

There's also the fact that cooling uses much less energy than heating because the temperature differential is usually much less extreme. It takes less energy to go from 100F/37C > 75F/23C than it does to go from 32F/0C > 65F/18C.