You need to diagnose something on your laptop that has stopped accepting input or with a blank screen. plug in your Android phone, enable USB tethering, ssh in.
You are on holidays, your need to help someone (or yourself) with some server issues. Use your teminal to ping them, ssh, etc. Later, no Internet at your rental house. No computers. Fire up the terminal,diagnose the issue. nmap the network if you need to find the IP of something (also, to check for cameras? IDK).
It's just a huge toolbox, batteries included. You might not need it. It can certainly come handy, especially if you have no Internet to download the corresponding app.
I don't use it often, but when I do, it's much better to have it than not having it.