Asking full privileges is a way of avoiding changing them on a update. If you change permissions on a update, chrome will ask for user interaction. That being

Asking full privileges is a way of avoiding changing them on a update. If you change permissions on a update, chrome will ask for user interaction. That being said, if you don't plan to broad the scope of an app or extension in the future, there is no point. This technique is applied on a lot of android apps too.