Indonesia seems pretty lackluster to me. A few free resources, some faith and a gimmicky swordsman.
The resources won't make them a filthy rich trader, or put them in regular golden ages. The swordsmen aren't going to win a domination victory by themselves, and the Candi relies on other civs spreading their religion as well as your city being on a river; it's a situational buff that you may not ever even see.
Compare this to someone more focused
The Zulu field larger armies, have what may be the most deadly pre-gunpowder unit in the game, and a barracks that puts their units on steroids. When it comes to war, the Zulu get things done.
The Portuguese can get many more free resources than Indonesia with their Feitoria, have potent trade routes and a Caravel that gives them free money because free money. When it comes to wealth, the Portuguese get things done.
What does Indonesia get done? Nothing in particular.