Oddly, here in Noway, you nearly always bag your own groceries regardless of the chain. You pay a little for plastic bags, which are always decent quality. Most people turn around and use those bags for their household trash.
I have gotten much faster at bagging groceries since I've lived here. I have never really had a cashier tut-tut at me for being too slow: but the bagging are is divided into 2 sections and sometimes they won't switch back to my side. There is some social pressure to be quick about it, but folks seem to understand if one has a lot of groceries.
Aldi has no problem with you reshuffling the stock on the shelf to create an 'empty' box out of two partially filled ones. I've gotten really good at this.
When you think about it, it also keeps the shelves a bit more organized when people are walking away with the cardboard that would normally have to be recovered and packed up by the employees.
Interestingly, Aldi's starts the payscale at double the minimum wage, or about $18/hr in the US