I HATED anyone else doing the bagging - unless they were also going to carry the bags to my car AND take them out at the other end and into the kitchen. Which wasn't going to happen ...
In Australia, the cashiers work with 2 bags hung on 2 separate rails in front of them. As you load your stuff on the conveyor belt, they not only scan, they selectively pick and place in the bags. The lighter stuff are set aside until all the heavy stuff are placed first. You don't have to worry as they obviously have been trained. So it real pleasure when you reach home to find everything in the right place.
Real boon to parents with kids, those with disability and I guess everyone else as the whole bagging is done by pros. When I came back, I bag like them having learnt from the pros.
Also the queues move a lot faster for obvious reason. On other thing distinct in OZ and NZ, the cashiers light hearted banter with customers while the scanning and bagging is normal, pretty much cultural there. Even when you enter a lift in both these countries with a stranger, greeting plus banter always.