Comment by RiverCrochet

In the U.S., particularly the Walmarts I've been to, cashiers are usually slower than the self-checkouts now.

Their self-checkouts used to be slow because the registers would verify the weight of items on the scale (the surface where you bag it) before letting you put it in the cart. If it didn't like the weight it would force you to put it back in the bag. I don't think they do this anymore. Asset protection can view a camera pointed at the scanner and bags if they think you're stealing.

Furthermore, it's hard for Walmart to retain people, so cashiers are treated like a dump stat. They won't really dedicate people to checking out anymore unless that's all they can do, e.g. elderly, so someone who's a cashier all day tends to be slow because they're accomodating that person. So you could be the fastest cashier in the world but it won't mean anything as far as raises, etc. Your fast cashiers are often pulled off and stocking unless its super busy.