Increased battery life for one. It used to be easier to toggle on older Android phones because there was a default shortcut in the slide-down menu, now it requires going through the settings at least on Google Android.
edit:
Huh, turns out you can add a toggle. I can't believe I never noticed that, thanks!
On newer versions of Android, I believe there ought to be an option to edit the slide-down menu in the slide-down menu itself. Expand it all the way, and look for a pencil icon. You should be able to add a location toggle that way.
edit: Huh, turns out you can add a toggle. I can't believe I never noticed that, thanks!