The world of Dragon Ball is in a constant state of mayhem and on the verge of utter destruction; and its citizens have no idea. Thus is the fate of the average human being on Earth in Dragon Ball. As godlike entities and monsters threaten the well-being of everyone on the planet, either no one is aware at all, or that they're made to conveniently forget.
Source：https://www.cbr.com/dragon-ball-anime-citizens-unknown-trivia/
