It's not just the time saved (which depending on the store, can be much more than 5 minutes - it's not rare that my parents have to wait almost 20-30 minutes at Costco, or that I have to wait 5-15 minutes in the line at the grocery store because dumb auntie at the front pays all her grocery with 5 cents pieces, people have huge grocery, etc. When you have to use public transportation to get back from the store to your home, a simple unexpected 5 minutes wait can easily transform in a 30-60 minutes delay in your daily routine.
And as I said, such automation could end up bringing the price of certain goods down. Automation is the whole reason you can afford electronics. It's the whole reason you can afford cars. Etc. It brought the prices of those things down drastically, because in the long run, maintenance of these machines cost less and are more efficient than paying a human working force. A single automated checkout machine (and i'm not talking about a self-checkout machine - these things are dumb) could easily achieve what 5-10 cashiers achieve in the same amount of time.
