All good points! When these kiosks started out, they were ridiculously laggy, way more than a simple GUI had any right to be, as if every tap and swipe had to be proxied through New Zealand. Thankfully the lag has been solved in one of the interface updates since.
The upsell spam is still annoying, but having used the interface a couple times I have become the Neo of offer dodging. Tap tap tap (No I don’t want to log in. Yes I am sure I don’t want to log in. No, I don’t want to make it a meal. No I don’t want to add a soda or side of nuggets. Checkout. Cancel payment. Done!) Would be better without, but currently manageable. As others have mentioned, they already managed to fuck up the tableau screens above the counter by having the images move around, so that if you want to know how much a medium fry would cost you have to wait through 30 seconds of slideshow first, and then not miss the 2 seconds that the price is actually on screen. The kiosk is actually the winner for me here.
The waiting in line to pay cash was my last problem, which is why I got excited to see these automatic cashboxes installed. Money goes in, food comes out.