As far as I know, a heat pump and an AC unit are essentially identical. Although some heat pumps can be reversed, and act as heaters in the winter. But one isn't more efficient than the other, they employ the exact same physical refrigeration cycle.

Oh, I had them filed in by brain under “more efficient temperature control” but it looks like they don’t have an advantage over ACs when cooling. (Just over typical heaters, when heating). Oops.

That’s true however moving heat in the winter is much better than burning things.

Gas furnaces are 80%-98% efficient, heat pumps are 300-400%.

I think GP's point is that winter heating can shift to nuclear- and wind-powered instead of mostly burning fossil fuels.