This makes sense for cars, where there's much local stuff to control. But for a home unit, what do you want to do that is entirely local? Turning the heat up and down gets boring after a while. If it does entertainment selection or shopping, it needs outside world connections.
(Today's rant: I recently purchased a humidifier. It's just a little unit with a water tank, a water-softening filter, and an ultrasonic vaporizer. That part works fine. Then there are the controls.
All this thing really needs is an on-off switch and a humidity knob, and maybe lights for power, humidification, and water tank empty. But no. It has five touch buttons and a round display about four inches across. The display is on even if the unit is off. Pressing the on/off button turns it on. If it's humidifying, there's a whole light show. The tank lights up purple. Swooping arcs of blue run up both edges of the round display. It's very impressive, especially in a dark bedroom. If you press and hold the second button for two seconds, about half the light show is suppressed.
There are three fan speeds, and a button for that. Only the highest one will propel the water vapor high enough to avoid it hitting the floor and uselessly condensing before it mixes with the air. So that feature was not necessary.
The display shows one number. It's usually the current humidity, but if you press the humidity set button, the number displayed becomes the setting, which is changed upwards by successive presses until it wraps around. After a few seconds, the display reverts to current humidity.
Turning the unit off or removing the water tank resets all settings to the default.
This is the low-end unit. The next step up comes with an IR remote. It's one way - the remote has buttons but no display. Since you have to be close to the display to use the buttons effectively, that doesn't help much. The step up after that is, inevitably, a cloud-based phone app.
So this thing could potentially be interfaced to a voice assistant. That's only useful if there's enough information coming back from the device that the assistant software knows what the device is doing, and the assistant software understands that device status. If all it does is send remote button pushes, the result will be frustration.
So you need some degree of intelligence at both ends - the end that talks to the human, and the end that talks to the device. If the user says "House, it's too dry in here", the assistant system needs to be able to check the status of the humidifier. Has power? Talking? On? Humidity setting reasonable? Fan running? Tank not empty? If it can't do that, it's part of the problem, not part of the solution.)