That's all true, but when you say "off the backs of others" that generally means by unfairly exploiting the labor of others without giving them anything back (s

That's all true, but when you say "off the backs of others" that generally means by unfairly exploiting the labor of others without giving them anything back (see every dictionary, or https://www.collinsdictionary.com/us/dictionary/english/live-off-the-backs-of-someone https://www.collinsdictionary.com/us/dictionary/english/live...). In the examples you have cited, all of those people were paid for their labor. In the cases of Winfrey and especially Jordan, many of those people were paid extremely well for their labor.