Life is either fair or it isn't, and it isn't. We all enter life through the lottery of birth, and conditions are markedly unequal. Inequalities abound, from physical to intellectual to socioeconomic.
Whether a person can improve their life in spite of the inequalities is another issue. There is no guarantee they can, but that doesn't stop most from trying. People who say, "You just have to make the best of it" are missing the point. A child who starves to death at the age of two has a hard time of making the best of it. That is the reality of life for some.