An induction-friendly stovetop kettle is a pretty great option as well, for those with induction burners. I have found it about as fast as an electric kettle, but it saves counter space, and won't have to be replaced every 1-5 years. Maybe I have just had bad luck with inexpensive electric kettles, but they kept dying on me.

A holiday rental I stayed in had a boiling water tap. It's a small improvement over a kettle, but in terms of improvement there's very little efficiency gains to be had over a hot plate directly in contact with the cooking liquid.

Once you've had one you can't go back. I don't know what the losses are from maintaining the hot water but it's the ultimate in convenience.