@Canageek@cybre.space they're increasingly a thing! They are genuinely an upgrade if you mostly drink things that don't want boiling water too

Random listacle with examples: https://www.alphachooser.com/electric_kettles-the-latest-variable_temperature_kettles
The Bonavita gooseneck mentioned there has a commercial cousin that is used in every single fancy coffeeshop doing pour-overs. But pretty much every mid range to high end appliance maker in the US sells a variable temp kettle these days (cheaper kettles are still just on/off of course)