If you want to go deep you can also cook your dinner while driving using the same principle. A copper pipe wrapped around the pot does the job.
That makes total sense if your presumptions are true. How sure are you about those presumptions? Also, just thinking logically: a microwave can be applied to the entire mass of water at once, whereas a heating element is limited to a degree by its locality within the water -- hearing the molecules immediately nearby first and then relying upon those molecules to transfer the heat further on down the line.