After Adam and Eve sinned, why did God not destroy the world and start over to achieve a better result?
The short answer is that a fresh start was unnecessary because nothing can thwart his ultimate success, including the messes we make.
God initially planned for us to commune with him forever while we lived blissfully in a perfect world of endless delight.
He did not abandon this goal after Adam and Eve sinned. Instead, he implemented a new strategy to achieve it.
God restored our ability to commune with him by paying the penalty for all sin through the death of Jesus.
In the hereafter, he will upgrade our bodies, renovate the universe, and bring heaven to earth. There, we will live in perfect harmony with him and each other.
And under the leadership of Jesus, we will build a cohesive society in which everyone thrives, individually and collectively.
Reborn believers will enjoy in the next life the utter bliss that God originally intended for everyone to enjoy in this life.