Imagine a situation when someone snatched your unlocked phone from you and does not want to give it away. It can be either your friend or an intruder. What to do in such a situation?
There are many options, but one of them is to enable the voice lock function in advance:
After that, being near the phone, you can say Lock screen / Lock screen.
As a result, the person who takes possession of your phone will not be able to do anything with it, since the smartphone unlock window will be displayed.