So far, I can think of no really good reason to have a wi-fi enabled major appliance. Yes, it might be nifty on rare occasions, but so very seldom, that it simply is not worth the security and privacy issues. I’m excluding TVs, since wi-fi can be a core function of how you use them for streaming.
Smart Appliances Bring Convenience, But Risk Your Privacy - Consumer Reports
We don’t have an Alexa or similar device, either (though if they ever let us change the code word to, say, Jeeves, I might rethink that!). I genuinely can’t see a need or use for one - unless such a thing would be required if we ever got a smart doorbell / lock. Or if we cared all that much about programmable lights or something.
Garage door opener: Yeah, I actually could see the utility of that. The security would still be a concern, however. We currently have a keypad on the doorframe that any of us can use to get into the garage from outside, and I have a key hidden inside the house, in case the door from garage to house is locked.
Video doorbell: I actually like the idea of one of those, but privacy concerns still outweigh the utility for us. If we were older and not as able to get to the door, or if we were out of the house a bit more, I might push to get one. Recently, I went to drop off something at a neighbor, and was amused to get a message from them - from a thousand miles away - checking in on what I was there for.
So far, the only IoT thing we have is an air filter I bought for my home office. It was a silly thing to get - really not needed. I just wanted to try it out. The only advantage is that because it’s connected, I can set up a schedule for it - lower speed during the work day, higher at night / weekend when I don’t care as much about the noise. Yes, I could change its settings from a thousand miles away, but I guess I could have lived without that feature 
A smart thermostat would be useful. “Brrrr, I’m cold. I don’t want to go upstairs / downstairs to check it. Lemme check the phone. OK, time to fix that!”.