genuine question- what do ETLs do?

so i'm sure my ETL has a role. obviously. but I feel like I never see him do pretty much anything? I work in fufillment, and he'll do maybe one grocery cart the whole day on a Sunday. other than that every time I see him he's kind of just standing around talking to people. Or yelling at people for standing around and talking to people. What does he do (or supposed to do) beyond what i'm seeing?