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.
so why do they have to cost 4-5x what it costs to get an Aircon installed?
I posted this elsewhere in this thread, but here seems good too:
Obligatory Technology Connections ( @TechConnectify@mas.to): Old HVAC industry practices are holding us back and costing us money. But we can fix it.
TL;DW (but you really should, it’s a great video): “Recommended” heat pumps are often oversized and overpriced compared to what is actually needed, and homeowners need to be aware of this.
Condensed version
Lobbying, probably.