Before we downsized 7 years ago, we had gas
C/H which was quite efficient and our monthly bill to heat around 2800- 3000 square feet and cook with gas as well, was considerably less even adding in electricity, than our current monthly bill for 100% Electric C/H, in a house of 1000 sq. feet.
So, the answer is no, but only because of cost – 9 kw boiler heater with wet C/H ,
even with a new thermostat , is very expensive to run.
We have purchased a couple of German ceramic heaters at 1.5 Kw which give off a lot of heat, so we use those rather than the C/H.