There are huge risks to operating any sort of physical retail establishment, well beyond managing the change in the tills. This doesn't mean the world would be better served if all retail happened online. The risks are worth the rewards.
Shop lifters are an issue but weight limits the value of what they could steal.
The shop doesn't have to pay for an armored truck to deliver the milk, a regular truck works fine because we don't have armed milk robbers.
There are risks in physical retail far beyond managing the shoplifting problem as well. In fact, theft of all sorts is only a small portion of the risk-pie here.
