Families all had rules with regard to Mystical Materials. Not even a future Family Patriarch could have all at his will. Otherwise, the other disciples would not feel fair and it would impact the cohesion in a family.
Of course, if a given future Family Patriarch was very talented, the other disciples wouldn't disagree if the family were to favor that future Family Patriarch.
Lu Renhuang was a case in point. After all, it would be good to the Lu Family if Lu Renhuang could be more powerful.
That being said, Lu Li and Lu Renhuang's status were quite different. Lu Li was even beneath Lu Suan and Lu Ni. What was more, Lu Zhengtan was the one in power right now. How dare Patriarch Four and Patriarch Eight just give Lu Li some Mystical Materials and other treasures?
