I think you could be right about washing machines/dishwashers, but as far as electric kettles... even at US 120V, an electric kettle is WAY faster at heating water to boiling than even my fairly powerful (bigger than traditional burner) gas range. (Not to mention much more energy-efficient).

I have no idea why electric kettles aren't more popular in the US.

But I never thought about the 110V/230V thing with regard to kettles. I guess even though electric kettles in the US are faster than the stovetop, they still aren't as fast as everywhere else with 230V? Maybe "faster but not faster enough" is why people still heat water on a stovetop here? I don't know!

Driers, and similar high power appliances, don't use a single 120V phase. They use two phrases, 180 degrees apart in normal residential houses and 120 degrees apart in apartment buildings. Any American clothing dryer I've ever seen has 240V (slightly less in apartment buildings.)