Electric teapots are generally made of aluminum or stainless steel, which will produce weak electrolysis during heating. This is a chemical reaction, and the reactant is a heavy metal substance. If it is absorbed by the human body, it is difficult to exclude it.
Of course, electric heating rods are generally made of copper, which will also hydrolyze during heating and hurt the body.
Moreover, the water burned by electricity is more likely to produce scale.