It's probably true that a well-integrated smarthome would benefit from voice control.

But I'd observe that I'm going up to my brother's tomorrow and he has all manner of timers and other WiFi-connected stuff and none of it has any sort of centralized control and that's pretty normal even for people who have a lot of that sort of thing.

And, yeah, the only smart light thing I have at home is one thing that doesn't have a controlling light switch and I used X10 for it for years before I got an Alexa.