5 minutes of running water at full speed to wash up dishes seems like way too much, unless it's a really large household. Washing up after a quick meal takes a few seconds, and if a proper dinner with cooking you'd fill the sink enough to soak the load then come back to rinse.
Running the water continuously is not recommended but for people who were not taught water-saving practices, it is likely the default way one might go about hand-washing dishes.
