The presence of Tao doesn’t mean that evil ceases to exist, only that it loses its power.
Certainly a different way to consider what to do about the existence of evil in the world; the conventional wisdom, and the mantra used in many cases to encourage a group’s willingness to fight, is that evil must be eradicated. Acceptance of the requirement that if there is good there must by definition also be evil and that, rather than eliminating it, we should act in a way that robs it of its power turns the whole concept on its head. This might be a good and necessary thing to do.
Star: It’s not that they (dark spirits) have no power, it’s that their power can’t harm anyone.