Personally, I’m faster and better at bagging my items. Most grocery stores don’t even bag your stuff for you anymore, so it’s actually much slower for me to wait for someone to scan my item, then slide it down the conveyor belt so I can wait for them to scan the thing that should be at the bottom of the shopping bag. Too much hassle. Yes, it’s fucking stupid that I’m essentially doing labor that someone who is actively employed could be doing, but I also don’t have all fucking day to wait in line ups.