I personally prefer self checkout at the grocery store because I get to bag my groceries the way I want to (grouped by frozen food, cans/bottles, non-food, etc.). It’s annoying to carefully group my items at the regular checkout conveyor only to have the cashier randomly bag them at the end. And even if I offer to bag them myself, I have to do it awkwardly while the cashier and next customer wait and stare, which isn’t the case for multiple self-checkout counters.