Note - because this is something which needs to be pointed out in any discussion of AI now - even though human beings also make mistakes this is still markedly less accurate than the average human employee.
(I say model, but for this problem I'd consider a pipeline where the powerful model is just parsing orders and formulating replies, while being sanity-checked by a cheaper model and some old-school logic to detect excessive amounts or unusual combinations. I'd also consider using "open source" model in place of GPT-4o, as open models allow doing "alignment" shenanigans in the latent space, instead of just in the prompts.)
> it's incredibly unsanitary
The key to me about the kiosks is: (1) initially, replace cashier labour costs with new expensive machines, and (2) medium-to-long term, upgrade the software with more and more "upsell" logic. This could be incredibly effective as a sales tactic. (Not withstanding the possibility, I fully agree with your final sentence!)
Can you imagine if a celebrity, like Kim Kardashian or David Beckham, lent their likeness for a fee to McD's to create an assistant that would talk with you during your order? (Surely, AI/ML can generate video/anime that looks/moves/sounds just like them.) I can foresee it, and it would be the near-perfect economic exploitation of parasocial relationships in a retail setting.
They probably ignore them, as they should - the same problem exists everywhere, from ATMs to door keypads to stores to self-checkout to tapping your card on stuff, etc.
> initially, replace cashier labour costs with new expensive machines,
Labor, like energy, is conserved in the system. It might be easier to counter proliferation of those systems if the narration was focused less about companies replacing labor on their side, and more on the fact that this labor gets transferred to the customers, who are now laboring for free for the company, doing the same things that used to be done better and faster by a dedicated employee.
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 goals - it's a platform for milking the users as much as possible."
Regarding sanitation, not sure if they are any worse than, say, door handles.
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.
It will depend on the material of the door handles. In my experience, many of the handles are some kind of metal, and bacteria has a harder time surviving on metal surfaces. Compare that to a screen that requires some pretty hard presses in order to get registered inputs from it, and I think you'd find a considerably higher amount of bacteria sitting there.
Additionally, I try to use to my sleeve in order to open door handles whenever possible.
About as unsanitary as opening the door to get to the kiosks. The kiosks get wiped down more than the door.
LLMs, if used at all, aren't aware enough to even know what the software can do, and many actual chat UIs are worse than that!
My "favourite" design pattern for chat UIs is to invite you type, freely, whatever you like, then immediately enter a wizard "flow" like it's 1991 and entirely discard everything you typed. Pure hostility.
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 agent could actually take orders with surprisingly good accuracy.
Now, whether we want that in the world is a whole different debate.