Humans have yet to solve the problem of interstellar travel. Any alien race that is able to reach Earth would presumably solve that problem and thus be more advanced than us.
There are fictional worlds that contain aliens who are on various stages in their evolution. Warhammer 40k for example acknowledges some alien worlds contain races still in the stone age, or in their medieval stages, etc, but they go to visit them. A stone age race isn’t going to come and visit us.
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