Maybe Aldi has unusually high professional standards. When I worked in retail as a teenager there was an obvious split between the adults who had been working there for ages (and were exceptionally skilled and quick), and the high school/college students who were there for summer jobs.

The majority of the employees were in the latter group and we didn’t have any special skill. I mean, lots of people work in retail when they are teenagers, so on average the people who have done that in the past are more experienced that those who are currently doing it, right? Unless there’s a skew that is causing people to stick around longer in retail jobs as time goes by.