People view the world through contrast.

To show Aladdin is poor, put him outside of an golden mansion. Have him go to bed hungry while the Sultan throws extra food away.

Spongebob is even more annoyingly naive when he’s standing next to the curmudgeonly Squidward.

Now that we have characters with opposing worldviews, the story becomes a wrestling match:

How do Aladdin and the Sultan view love differently?

How do Spongebob and Squidward respond differently to working a dead-end job?

This wrestling match becomes even more interesting when the two characters have a lot in common but come to different conclusions:

Peter Pan and Captain Hook both fear growing old and dying but in the end Hook gives in to despair while Pan realizes “To live would be an awfully big adventure.”

Frodo and Gollum both desire the One Ring, but while Gollum seeks to kill Frodo, Frodo clings to hope and redemption. He sees himself in Gollum and refuses to view him as a monster.
In the end, both characters give in to their addiction to the ring as they fight on the edge of Mount Doom, but Gollum wins and gets the ring. As he falls into the lava below we see the that greed and corruption are self-destructive. Frodo is saved by his friendship and mercy.

See, these are not just characters - they are the embodiment of conflicting ideas.

When Professor X and Magneto play chess, it is a philosophical debate about how we respond to persecution. Magneto is willing to sacrifice his pawns to go on the attack, Xavier plays defensively. This reflects their ideas about the oppression of mutants - non-violence vs. armed resistance.

Batman fighting The Joker is a reflection of how we deal with living in a chaotic world - seeking justice, control and hope vs. nihilism and destroying of broken systems.

These stories really strike a chord when the two ideas being contrasted are both valid. In life we all have to decide where we stand on these moral questions and it is the power of storytellers to make these ideas real through characters.

I believe a powerful ending involves neither side “winning” but a new reality being established. the villain is vanquished but the hero is forever changed.

ps

Contrast is one of the principles of visual design, I’m curious about how the others could be applied to writing and animation.