Heat pumps have a COP value of around 4 to 5 (10 to 15C outdoor) and 3 (0C outdoor). The seasonal COP (or SCOP) measures the efficiency over a whole season, and that typically sits around 3 to 4. That means that for 1kWh of electricity a heat pump delivers 3 to 4kWh of heat to the house.
Burning gas to heat a home means "1kWh" of gas, delivers ~1kWh of heat.
Modern gas power plants are about 55 to 60% efficient, so "1kWh" of gas becomes ~0.57kWh of electricity, which after transport losses (-6%) arrives at the home as 0.52kWh, which gets turned into 1.5 to 2.0kWh of heat.
=> It's almost two times as efficient to turn gas into electricity and use heat pumps in the home
The ceiling is not 100% efficient, when you have a heat pump.
Also, the US residential gas infrastructure leaks ~1% of the gas it moves. That sounds like nothing, until you account for how unburnt ch4 is ~80 times worse than co2 on a timescale of 20 years.
Burning gas to heat a home means "1kWh" of gas, delivers ~1kWh of heat.
Modern gas power plants are about 55 to 60% efficient, so "1kWh" of gas becomes ~0.57kWh of electricity, which after transport losses (-6%) arrives at the home as 0.52kWh, which gets turned into 1.5 to 2.0kWh of heat.
=> It's almost two times as efficient to turn gas into electricity and use heat pumps in the home