My teenage children often leave lights on in the basement of my home. "Alexa, turn off the basement lights".
I'm also slightly afraid of heights, so I've considered installing smart LED's in the can lights in the eves of my roof. "Alexa, turn the house red."
Sometimes I get hot or cold after I've already gone to bed and I don't want to walk to the thermostat to see if someone has adjusted it. "Alexa, set the temperature to 70 degrees."
I worry about the loss of privacy but the day to day convenience is also pretty compelling.