If I have a large amout of stuff I'll go to a human checkout. But for any amount up to what will fit on the bagging area of a robot machine, then the robot is usually my first choice.
At a conventional checkout, you lift all your stuff onto the counter. You can try and do it in the order you want things to be packed but the cashier won't necessarily scan in this order. Then as soon as you have done that you have to rush round to the other side and start putting things in bags. Usually this has to be done in a bit of a hurry as you will be asked for payment before you're quite finished. So then you are trying to do the card payment simultaneously with packing up the remaining stuff. Generally you feel under time pressure because there's someone behind you in the queue whose stuff is already piled up and, if you've done your payment, the cashier will already have started scanning their stuff through. So then you end up with a load of half-packed items to take somewhere else and sort them out properly.
On the other hand with the robot, you can generally take your time. Pick up item, scan, straight into bags in the order you want. Pretty much one action per item instead of several with a human checkout. No feeling of time pressure. Work is removed from a cashier but I don't really feel it's transferred to me. I have to do some work either way, and with the robot it's actually easier work.
Please don't call it a robot. That makes the robots sad.