Is life futile? If so, why?

I said in my heart, “Concerning the condition of the sons of men, God tests them, that they may see that they themselves are like animals.” For what happens to the sons of men also happens to animals; one thing befalls them: as one dies, so dies the other. Surely, they all have one breath; man has no advantage over animals, for all is vanity. All go to one place: all are from the dust, and all return to dust. Who knows the spirit of the sons of men, which goes upward, and the spirit of the animal, which goes down to the earth? So I perceived that nothing is better than that a man should rejoice in his own works, for that is his heritage. For who can bring him to see what will happen after him? Ecclesiastes 3.18-22