this can happen for language change

This is true and in that case, it’s okay for my apps to restart from the home screen. I haven’t had anyone complaining about that yet. People don’t change the language of their phones that often.

resizing of your activity, keyboard opening,etc

These changes can all be handled by setting the appropriate flag in the manifest. A simple layout pass and everything works fine again without losing any state.

anything you have in your UI, should be able to save whatever it needs so that if it gets recreated has everything to get the user to the same state he was before the configuration changed

Well… if it gets recreated only when the language changes or when the app is killed after being inactive for a couple of hours then it’s perfectly fine to restart from the home screen. That saves a lot of code.