That's fine, but there are no use cases in the US. If we are boiling water, it's for food, and we're doing it on the stove, just like the way everyone else cooks. In the US, there is no use case for a specialized water boiling appliance.
We can agree they're less common than the UK, but saying they have "no use case" is a gross exaggeration. Pretty much everyone I know owns a kettle, given how cheap they are (~$15-20 for an OK one). Great for hot chocolate, coffee, tea, boiling water for a pot of water (to speed it up vs heating up your entire house), and numerous other reasons.
I have been known to heat water in a microwave after doing the calculations needed to know roughly when the water would reach boiling. It is rather quick once the microwave timer starts going.
