Before they left this planet though, they had to find a place to go.
This world wasn't like the Blue Star Planet which had already been linked up with an upper realm.
This world was a mortal world, which meant that it had no contact with any upper realm since they didn't even have a concept of cultivation. So there wasn't a passage that Lin Fan could take that would guide him up to an upper world.
Since that was the case, it meant that to reach an upper world, Lin Fan would have to rely on his own cultivation to break through the atmosphere of this planet and fly through space to reach another planet. Well, not just another planet, a planet that actually had life and other cultivators on it.
So even if he were able to reach another planet after braving the stellar winds found in space, he might land on another planet that didn't have any living beings on it, which defeated the purpose of leaving this planet.