It illustrates a flaw with Imu trying to maintain eternal life for himself and his followers.
Luffy states that the thing wrong with not wanting people to die is "people die." It's a fundamental rule of existence of people existing in a normal state of life and death.
Essentially, you're no longer a person if you can't die due to the fact a fundamental rule of life and death is people die.
There is much more to it, and it has currently been interesting me.
We know Oda is fond of hinduism and in hinduism we know that the concept of the "Samsara" exists.
A perpetual cycle of life, death and rebirth, something Oda symbolizes in many ways, for example the devil fruits and inherited will.
Another big cycle that's important in this regard are the world cycles and reincarnations of the sungod.
World 1 -> World 2 -> World 3, Nika -> Joyboy -> Luffy
We can henceforth assume that if Luffy were to fail and die, he would become reincarnated and the world would move to world 4.
In hinduism/buddhism/jainism, this is all considered to be a giant trap, your soul is trapped and the soul can only reach it's completed and final stage by transcending beyond this cycle and breaking through this duality between life and death.
That's why the people of the Will of D are smiling when dying, it's their ticket to a finality, to the transendence.
The Will of D is nothing else than the will to break out of the Samsara, and that is why Luffy's dream is to obtain this freedom, aka to transend beyond.
One Piece fundamentally is about that, a story about breaking out of the system and seeking out for the transcendence after the life.
Vivi/Lili in this story is probably a confused soul that is trapped between Life and Death and Luffy symbolizes the anchor, the access to the higher consciousness (Akasha) or a prophet/godlike being that reaches their hand out in order to help people transcend aka become free.
All the people Luffy saved were people that spiritually awakened and turned themselves towards god. This is why when Vivi got reintroduced after Zou, we saw her jumping off from the Alabasta's ship lookout platform or so - it was her way to express her freedom and that she is ready to transcend/become free.
That is Liberation
And then there is Destruction, aka Teach.
That's why he has the Earthquake fruit which symbolizes the cracks into the earth aka, the incomming destruction of the world -> This is Teach's way of breaking the cycle and free everyone by perpetually ending the cycle of rebirth and pain.
That's why Oda chose pain as a gimmick for Teach.
The inversion is real and it is all based on hinduism. And all those monkey powerscales and LARPer have no clue what the story is really about smh.
