Right where it's always been. And eventually, right here.
Solomon's saying the earth outlasts us, not that God is stuck with a temporary planet. Scripture never promises demolition. It promises renewal. The meek inherit the earth. Creation groans for liberation, not a scrapyard.
The story doesn't end with us evacuating upward. It ends with heaven coming down. God dwelling with man on a new earth, same creation purged and glorified, the way your body gets raised as your body.
Ecclesiastes gives you the stage that outlasts every generation. The gospel tells you who fills it.