I think that Oprah was bound to do great things because she was a hard worker and worked hard to get where she was, now whether or not it was philanthropy or television that was the reason for her skyrocket to fame then I think it was philanthropy that lead to telivision that lead to fame.
If philanthropy made people famous, there would be a lot of independently wealthy people who are extremely famous. She is famous because of her show, of course. It was one of the most-watched television shows of all time. If Oprah never had that show, we would have no clue who she is.
Although she has done some great philanthropic things, she gained notoriety by being on television. After she became well known on television, it opened some doors for her to pursue her philanthropic ideals. She had an ease and grace on television that attracted people to her and her audience expanded because of her personality. When her audience expanded, so did her ability to help others.
Her rise to fame came from the train wrecks she'd feature on her show, which got people talking. She never would have reached the level of philanthropist she has if she didn't have the vehicle of television to make her relevant, or for that matter have the resources to do so.
I believe that it was television that made Oprah Winfrey famous. She was one of the first prominent black women to host her own show on television. The television show along with some movie appearances were what made her rich and famous enough to partake in philanthropy. The philanthropy probably made her more famous, but she got the funds for it from television.