The article doesn’t go into it, but a key advantage they have is that heat pumps move heat, rather then trying to generate it. So they can move a lot more heat into your house than would be generated by running the electricity they use through a resistor. This makes them effectively more than 100% efficient (the exact amount depends on temperature) as compared with burning a fuel or resistive heat.
Straight up since my grandma got one installed at her house she hasn’t had to use her in wall heaters or her fireplace
And in AC mode that thing is great