What is the wisdom behind not allowing the son of the son to inherit when there is someone who disinherits him?

The grandson does not inherit when the son is present because it has been authentically narrated from the Prophet, may Allah bless him and grant him peace, that he said: "Give the prescribed shares to those who are entitled to them, and whatever remains is for the closest male." And the son is closer to the deceased than the grandson, so he has a greater right to his wealth.