I would think that in a grocery store, the registers are deeply integrated with the inventory control. That's not needed in a restaurant, registers just collec

I would think that in a grocery store, the registers are deeply integrated with the inventory control. That's not needed in a restaurant, registers just collect cash/card. So, in the former, catching up is much harder - you might need to take an inventory if the outage is lengthy, which is a PITA. The requirements probably didn't include offline mode.