What do you think is the more thought provoking concept? If you didn't know, the Egg of Lilith is from End of Evangelion (the epilogue film of Neon Genesis Evangelion) and involves fusing everyone's consciousness together in a single "organism" so that everyone can exist with perfect understanding and acceptance of each other, and would essentially be part of the same consciousness and share all feelings and thoughts, so people can no longer hurt each other through rejection, cruelty, etc thus making it a "perfect existence" for humans who are social creatures at core. Shinji becomes the god of this united world of minds and rejects it because of how it is "fake" and to truly live is to be accepted by others by their own will, causing the moon sized "egg" to break apart and release people's essence back into the world in a sea of LCL.
Madara's World of Dreams is similar but different. It's a bit more straight forward, everyone gets placed in an infinite genjutsu where they imagine themselves in their own perfect world for eternity, everything existing to make them perfectly happy and content with themselves and life while being unaware of the artificial nature of their reality. In theory it truly is a perfect world, but like the Egg of Lilith it's artificial perfection and not earned through free will.
Madara's World of Dreams is similar but different. It's a bit more straight forward, everyone gets placed in an infinite genjutsu where they imagine themselves in their own perfect world for eternity, everything existing to make them perfectly happy and content with themselves and life while being unaware of the artificial nature of their reality. In theory it truly is a perfect world, but like the Egg of Lilith it's artificial perfection and not earned through free will.