Why does the author claim that family members are not reliable companions for one's spiritual goal?

The author in Chapter 45 argues that worldly relations, including family, are not reliable companions for spiritual attainment because their motivations are tied to the transient world. The text posits that even loved ones like a mother, father, son, or wife act out of self-interest. For instance, a son will be focused on the wealth he can claim, and a wife will mourn her own potential widowhood. No one among them is a true companion in the spiritual goal. The text concludes that upon final reflection, only one's own self remains at the end to pursue and achieve the spiritual objective, highlighting the need for self-reliance on this path.