Option 3, intelligent life that builds a civilization is not common in the universe, so they want to study us. Much the same way we study great apes or dolphins.

In that case, they might want to observe us without interfering to see how we behave naturally. Or maybe they have a sort of prime directive. Or maybe they realize that if they interact with us and expose us to their level of technology, we might destroy ourselves given the level of conflict and violence we're still prone to.