When you say it’s common, are you talking about heat pumps or old-fashioned resistive heating? I’m not very familiar with heat pumps since they weren’t common at all when and where I bought a house, but at least where I lived it was normal to have either an oil or a gas furnace for heating. Resistive electric heating cost a lot more to operate and so it was generally used only where it would be too difficult or expensive to install a furnace and hot water pipes or hot air ducts. For example, some friends of mine lived in a 19th century house which was meant to be heated by a wood fireplace and they also had electric heaters in the bedrooms, whereas my own house was built in 1980 so it had an oil tank, a furnace in the basement, and hot-water radiators.

(My own house also had a modern wood stove in the living room and buying firewood was even cheaper than buying heating oil, but the problem was that the wood stove took a lot of work and it only heated the living room since it wasn’t connected to any mechanism for spreading the heat to the rest of the house.)