The thing everyone should be aware of is that societal harmony is not done by just making the rules and defining human rights. Unless, the courts in the country are not providing justice to the people then the laws, rules and regulations are of no use. Societal justice is not a new concept, it's just a new term to make people realize the importance of societal harmony. The term societal justice means having Far relationships, connections, and dealings'' within a society. Following are the reasons why justice is utmost important thing in any society:

Everyone enjoys equal rights as no one is beyond the law.
Minorities and disable persons are provided with unique facilities and rights and no one can make them inferior from others.
People are protected from patriarchy and communal or religious discrimiantion.
Old-aged people's rights get reserved.and they are provided with facilities in the age when their own kids do not suport them.

https://www.humanrightscareers.com/issues/10-reasons-why-social-justice-is-important/