First of all, that’s not really what protagonist means.

It is also explained in the film, when the rest of the world knew of vibranium, wars were fought constantly over who would control it. This is why they went into hiding in the first place, because at the time, the world couldn’t handle it.

The villain (the antagonist) doesn’t want to help people as much as he wants to kill their oppressors due to his misplaced rage of being abandoned as a child. It’s definitely a tragedy what happens to him, but his motives and methods are wrong, even if he does have a point Wakanda could be doing more to help people.

The hero learns from his father’s mistakes and takes Wakanda into the public eye again in the end. It’s not that confusing. The villain has a point, but he is by no means a hero or a protagonist. He’s a tragic figure they couldn’t save.