>>508769478
I'm not sure if they use the same system in the US but in the UK we have little hand scanners or phone apps so every time you pick up an item you scan it and put it straight into your bag. I prefer this because I can pack my bags properly and don't have to juggle items because the wagie is throwing them down a conveyor belt at 200mph.
When you get to the self-checkout you scan the barcode, pay and leave.