Because there's no real objective truth about it, it's just what you tell yourself. If you think people only deserve success because they worked X amount, that

Because there's no real objective truth about it, it's just what you tell yourself. If you think people only deserve success because they worked X amount, that's a thought formed by social norms and, most likely, what you were told and how you were treated by your carers when you were growing up. The question is which of those beliefs will be more conductive towards actually achieving success and being happy? Instead of trying to guess which is true on some abstract sense, adopt one or the other, and empirically live your life by it for a while, and see the results.