In summary, the main question is whether induction water heaters have any benefits over traditional electric resistance coils. On Quora, someone argues that resistance coils are a near perfect conversion of electricity to heat, making induction heating unnecessary. However, induction cooktops are more efficient due to less waste heat between the coil and pan. This raises the question of why induction heating is not used in water heaters. Some argue that there is no advantage to the greater complexity of induction heating compared to a submerged resistive heater. However, others point out that heat pumps are more efficient than resistive elements, but they have different requirements and limitations. Ultimately, the efficiency of a heating system depends on the specific device and its specs.