Mentioning family and wealth among the things that return is not a dismissal of their value. Loving and supporting relatives, dealing justly with them, and managing inheritance fairly are meaningful duties. The lesson is to keep those responsibilities directed toward righteous conduct.
Example: A person handles an estate honestly and does not withhold the lawful rights of heirs. How the wealth was handled is itself part of the person's record of deeds.
In يَبْقَى عَمَلُهُ, عَمَلُهُ is the subject of يَبْقَى. The emphasis is on the persistence of deeds, not contempt for family or property.