

what you’re describing is an oven with a heat pump. industrial-grade ovens like this exist, but they don’t really exist in the home appliance market as the amount of energy recaptured at that scale would be negligable. it’s easiere (and cheaper) to make ovens more energy efficient in other ways.
there are a number of other home appliances (washers, dryers, and dishwashers), however, which use inverter heat pumps to recapture/recycle heat, thus increasing energy efficiency by quite a lot.
Considering that heat rises, I’d be pretty surprised if the heating element for an electric kettle was anywhere but beneath the tank. It wouldn’t work very well otherwise, unless you used a much more expensive method of heating it all around., But even then, there would still be heating elements underneath.
A good way to improve efficiency there, would be to insulate the tank to reduce heat dissipation in the first place.