It's the supermarket self-checkout UX horrible -> I'm automatically treated as a criminal because I can't checkout the next item before bagging the first. I have two hands darnit!
My annoyances are particularly as compared to Japanese-style ordering machines, which in my experience are simple, reliable, fast, and easy to use. My complaints, off the top of my head:
* Responsiveness to touch feels about a decade behind consumer capacitive touch displays.
* Gratuitous animations are slow.
* For a simple order where you know exactly what you want, there are far too many steps. (IIRC, for a black coffee, the button tapping flow goes something like this: English -> Hot Beverages -> Coffee -> Small -> Add to Cart -> Checkout -> Paying with card -> Paying with Bank card.) And you have to deal with the slow/bad touch response and animations for every one of these screens.
* There's no way to avoid the machine spitting out a BPA-covered thermal paper receipt. (Other than the receipt dispensation being out of order, which happens pretty frequently.)
> It's the supermarket self-checkout UX horrible
Oh, we have our own egregious example of that up in Canada, where the largest grocery chain in the country got rid of most of the text on self-checkouts in favour of just icons: https://www.blogto.com/tech/2018/05/loblaws-self-checkout-sy...
You shouldn't have to waste mental bandwidth on that needless bullshit - the only reasons are price point sleaze.