Clarification: resistive heating is very near 100% efficient, meaning that all of the energy you pull ends up in the air or water it is meant for. Gas water heating is at the very best ~90-95% efficient (e.g., top-end condensing tankless water heaters), but often as low as 60%: plenty of heat going out the exhaust. You think resistive heating is inefficient because policy has made electricity much more expensive per kwh than gas/oil.