I think NG outperforms in high efficiency heaters when the outside temperature is around 1-4 degrees Celsius with humidity as it causes ice buildup on the external unit which then has to be cleared using resistive heating. Also if only little hot water is required sporadically, heating it just in time with gas is more efficient than keeping a buffer heated for long times.

Also, heat pumps do best when the temperature differential is lower. So in older housing without floor heating or duct heating, it is typically not as efficient to use a heat pump when the water to heat has to be above 55 degrees Celsius.

For any new residential construction I think there is very little value in natural gas.

Methane has lots of value in colder climates, especially much of Canada. Methane is cheap and does not lose heating capacity as temperature falls. Across most of Canada, the median construction year for a typical house is in the 1980. Half were built before that, meaning insulation standards were lower.

The #1 problem with heat pumps in Canada is low temperature performance. The heat output drops but the rate of heat loss from the house also increases. This is the precise situation where even backup resistive heat cannot keep up. Methane is excellent at filling this gap, especially now when winter temperatures swing more than earlier.