they make these things called bags. but hey stranger, i appreciate you and everyone like you - i can't remember the last time i waited in a checkout line because i'm in and out of self checkout in like 2 minutes even at peak hours. it's amazing. i've also noticed that even the parking lot is less crowded at stores with self checkout. i'm sure someone has simulated this extensively because i can see it with my own eyes.
yet another job where i can, in fact, actually do it better myself. i'm just as fast on the self checkout machines as the cashiers are on their point of sale systems. the buffered queue also helps tremendously, instead of the line lottery of checkout lines. again - simulated and optimized.
the other people that do self checkout are also basically young-ish, single/alone, and would rather be anywhere than the fucking grocery store checkout line. separating people who are interested in getting the fuck out of there with food from the people who are slow, clumsy, and deliberately take a long time to make sure all their tiny little nitpicks are addressed by a captive employee audience is the best thing to happen to groceries in the 30+ years i've been wasting my life 15 minutes at a time at stores.