This is easy.
DialogFragment is a fragment.
So what can a fragment provide you while other objects can’t?
It’s the lifecycle callbacks.
So with DialogFragment, it can be very powerful and makes your code much cleaner.
Have you ever seen window leaks if you didn’t close a dialog when its Activity was getting destroyed? So to prevent that, have you ever tried to close the dialog when onPause() was called? So to do that, have you ever had to make a reference of that dialog to a class level object?
With DialogFragment, it’s all handled.
And you get all lifecycle callbacks.
Then you can provide more intelligence to the dialog and make it do some smart work on its own rather than Activity telling it what to do.