Ah, Benatar... I've been there! I spent a good amount of my depressed years quoting Schopenhauer and the likes... I would say that these arguments rest on a dichotomy of pleasure and pain which is... at least not universal, even if it is real for some people. We do not simply desire pleasure and an escape from pain. There are pleasures we run away from and pains we absolutely love. If you have ever been truly and madly in love, you will know what a torture it is, and yet... it is the most beautiful thing ever! to spend your days and nights constantly thinking about someone, while feeling stupid about it, experiencing the entire spectrum of human emotion, from gut wrenching anxiety and sadness to the extremes of joy and happiness, all within a single day.... its madness, and yet it is beautiful! What makes this existence worthwhile is the existence itself... life is what we truly like, and death is what we truly despise. Monotony is what kills us, and that monotony can be found in pleasure as well as in pain. And in the moments when you truly feel alive, you don't ask about the big purpose of it all... because the question itself is absurd.
The question of meaning and purpose comes from a certain place and a certain mindset. If you turn things around for yourself... it loses all its meaning! It is suffering what forces us to ask about the point of it all (and in some ways, perhaps bland happiness as well). There are ways to avoid the stupid and pointless kind of suffering, and there are ways to find the enjoyable kinds of suffering. Beauty can be found everywhere, in the good and the bad, in the pleasurable and the painful. Beauty makes it all worthwhile... when you experience something so beautiful that it leaves you speechless, thoughtless and struck with awe, you don't ask about the meaning and purpose! the experience suffices for itself.