RJ wrote:
It SEEMS
I can heat water faster in my microwave
than I can on my stovetop.

Is a microwave "more efficient" at heating water ?

If so, can anyone see a time where
the heat source for a home water heater
would be microwave rather than heating elements ?

The microwave heats faster cause there is no warm-up time.

No
AND be carefull to never heat plain water in a MW as it may damn near
"explode" when you go to use it due to surface tension issue.
I.E. put cocoa in before heating, ditto tea bag.

Lou