One point to note about elements:
Years ago (and I means years) electric water heaters had a external element which was strapped around the outside of the tank near the bottom. Heat was transferred through conduction through the tank and into the water. Some of the heat was also lost outward rather than into the tank.
This design was replaced by the current design of the immersion elements which heat by conduction/convection with no direct loss of primary element heat.
The current design of upper and lower elements provides the “quick recovery feature” which the strap element did not.
But the initial design fostered long element life since the element did not contact the water.