Injustice is a big problem.   But it's always a symptom of a deeper cause.

Wherever people aren't getting their fair share, you'll find patterns of decisions being made without genuine participation of people affected by them.

You can't build lasting peace and you won't get justice if people feel excluded from decisions they care about.  That works sometimes for a little while but in the end things fall apart.

If you want to fight for justice, go for root causes. Fight for good process, starting with the groups where you hold power or influence. If you don't make good process a priority there, your base will eventually collapse and everything you've done will be lost.