"electric kettles"?
I think you are taking about a percolator.
Here is a kettle from the ‘60s. It was only for boiling water.
http://www.canadiandesignresource.ca/housewares/k-42-electric-kettle/
My sister told me she couldn't buy one when she lived in Kentucky. We had to send her one.
It's probably because you don't drink as much tea as we do.