https://www.webnovel.com/book/all-of-mankind-crossed-but-i-was-forgotten!_24429596306652305
Title: All of Mankind Crossed, But I Was Forgotten!
Synopsis:
The earth is about to evolve to another stage.
In order to avoid the extinction of mankind, God sent all mankind to a different world with magic and powerful beings in order to make humanity grow stronger and gain powers, but the protagonist who was already a forgettable existence to even his own ex-girlfriend was left on Earth!
Left alone, the protagonist must fend against the coming powers of different races that were awakening on Earth, and must create a new utopia built from the remains of his former home!