> But still more expensive than gas in most areas?

Using numbers from the non-profit Efficiency Maine, with natural/methane gas at $2.561 per CCF (therm), and electricity at $0.1595 per kWh, standard efficiency heat pumps have better $/MMBtu down to about 0F/-18C, and high performance HPs down to about -10F/-25C, per this presentation:

* https://www.youtube.com/watch?v=OcwIz6heDss&t=39m30s

You'll have to do the math with your local prices. The same channel also has a presentation on dual fuel / hybrid setups:

* https://www.youtube.com/watch?v=T_9P3Dn7is0

Generally: if you're buying new HVAC+D equipment for your home, you might as well buy a heat pump instead of a 'simple' AC unit, and there are heat pumps that can work down below freezing quite well (which is probably good enough for most of the US population, except in the coldest locations).

And if you're building a new subdivision or apartment block, you can skip the entire gas system connection. Safer and cheaper.

Places off the current gas grid are also low hanging fruit generally.

i would say if you have a gas HVAC there is little point in replacing unless you also have a lot of solar on the roof and sending a lot back to the grid.

If I was building a new home today and in an area that might get down to 10-15F as a low i'd 100% do heat pumps. The nice part about heat pumps for me is that they might get to temp and run at 10% all day long and keep the heat right at 71. Where a gas will turn on at 69 and heat till 73 and continue that cold/hot cycle

being cheaper also depends on current utility rates also

As a nonamerican, I'm not sure how to read "most places" here. Do you mean most places in the USA or actually most places in the world?