I don’t know why you’re being downvoted without anyone actually debunking what you’ve said, so I’ll try. You’re right about not having another appliance being convenient, but I doubt a microwave is just as effective. If you’re just heating a cup of water, then yes. But boiling even a liter of water would take about 5 minutes in a microwave on the highest setting, which would take about 2 mins in a kettle. Not even taking into account that actually boiling water in a microwave is near impossible, because it would spill everywhere