It’s very inconvenient to remove off the USB power cable from raspberry pi, it also damages the main board of Raspberry pi. This cable can protect the USB jack, and your RPI board.
It can also used for your any other digital devices, for example, it can be power off when your charge your phone.
Simple micro switch that can be used as a limit switch, as a drawer switch or whatever you'd like. It even support higher current loads, so you can switch motors or high power leds with it (hint hint).