The Yuan clan was thriving when Yuan Haoran was born. However, the family structure was not stable. The fights in the family were intense, with each member of the family attempting to get the upper hand in the internal conflicts.
Moreover, despite the economic success of the clan, they did not have a lot of access to the rare material.
On Martial Island, lacking the rare material meant being vulnerable to disease and early death. Also, without martial power, families were in danger of extinction because the rules of the jungle were acceptable on the island.
As long as someone had enough power, they could kill and steal resources.
The Guardians were only concerned about external threats instead of internal ones. They would only interfere with the internal conflicts on special occasions, particularly when they believed that the fights would affect the entire island.