I think it's because of a shift to mobile and setting screens that autosave. Using on/off switched is a common convention on mobile operating systems like iOS.

I think it's because of a shift to mobile and setting screens that autosave. Using on/off switched is a common convention on mobile operating systems like iOS. When you are setting up something without hitting apply, the sense of activating a switch seems more like committing to the change compared to the checkbox.