Why does the author suggest that worldly relationships are insufficient for achieving one's spiritual goals?

Chapter 45 argues that worldly relationships are unreliable for spiritual progress because they are often based on self-interest and cannot provide ultimate support. The text observes that while a mother and father show affection, a son will be focused on the wealth he can inherit, and a wife will primarily mourn her own widowhood. No one, whether in-laws, sons-in-law, or a wife, is described as a true companion in the spiritual goal. The author concludes that upon final reflection, a seeker must rely on their own self to achieve their spiritual aim, as others will not be there in the end.