With so much technology....why stores still need to call other stores

This has nothing to do about education but I was shopping over the weekend and just don't understand why when you ask if another store might have an item that they have to call the stores to ask. With all of the technology that we have, why can't they just enter the information into their computer system to see which stores carry the item? I had to ask at 2 different stores Saturday and both stores not only had to call but had trouble calling the other stores. It got so frustrating that I thanked them for their help and went home and called stores myself. In the age of technology, this should be so much easier to do.