I will put one other mistake in there, is self checkouts with too many prompts. I avoid using self checkout at a few stores because the minimum number of prompts is higher than 3.
Good: scanning starts the process, select done AT MOST asks for how many bags, then payment type, swipe and pay (optional email receipt on pin pad).
Bad: Cant’ start till you tap start, asks for member ship card up front, asks if you want to donate, scan, asks if you want to use your rewards, asks for number of bags, also would you like an email receipt?