Earlier quoted context omitted.
I think the chat interface is bad, but for certain things it could honestly streamline a lot of mundane things as the poster you're replying two stated. For example, McDonald's has heavily shifted away from cashiers taking orders and instead is using the kiosks to have customers order. The downside of this is 1) it's incredibly unsanitary and 2) customers are so goddamn slow at tapping on that god awful screen. An AI…
McDonalds is a good example. In the beginning the Kiosks were a real time-saver, and you could order with a few "klicks". Today, you need to bypass "do you have the app", "do you want fries with that", "do you want to donate", "are you sure you don't want fries?" and a couple more. All this is exactly what your parent comment was saying: "To a business, the user interface isn't there to help the user achieve their go…
What I wrote earlier, about business seeing the interface as a platform for milking users, applies just as much to human interface. After all, "do you want fries with that?" didn't originate with the Kiosks, but with human cashiers. Human stuff is, too, being programmed by corporate to upsell you shit. They have explicit instructions for it, and regular compliance checks by "mystery shoppers".
Now, the upsell capabilities of human cashier interface are limited by training, compliance and controls, all of which are both expensive and unreliable processes; additionally, customers are able to skip some of the upsells by refusing the offer quickly and angrily enough - trying to force cashiers to upsell anyway breaks too many social and cultural expectations to be feasible. Meanwhile, programming a Kiosk is free on the margin - you get zero-time training (and retraining) and 100% compliance, and the customer has no control. You can say "stop asking me about fries" to a Kiosk all day, and it won't stop.
It's highly likely a voice chat interface will combine the worst of the characteristics above. It's still software like Kiosk, just programmed by prompts, so still free on the margin, compliant, and retrainable on the spot. At the same time, the voice/conversational aspect makes us perceive the system more like a person, making us more susceptible to upsells, while at the same time, denying us agency and control, because it's still a computer and can easily be made to keep asking you about fries, with no way for you to make it shut up.