Sadly.... it actually does make sense. 
At the very end he had the life that rebirth would have gave him, he just worked for it all, instead of having easy mode throw it in his lap.
He caught some feelings along the way. People that would give their lives for him - I imagine that would be one real dozy of a connection to have.

It is just and ending with out the finality of a permanent ending. (Even if he killed the super Evil Villain and saved the world with sacrificing the "Ultimate Reward") It basically ended with him shifting into "normal mode" without a reason to constant try to have his life ended by proxy. That basically cleared the meaning of the title, Kind of rare that the Author was so on point from my personal experience.

This is really just a twisted story of failing upwards... I almost want to root for his death, but at this point it feels like dying and getting immortality would actually take longer.