I believe this dual world might be part of a perfect divine plan.
But I'll add something to your post, let me know what you think:
There were a few times in my life where I was able to experience the unity. I've felt there was no duality at all...
I believe that it is possible for us, when we left this realm, to return Home. And I feel that duality doesn't exist there. Only love, oneness with the Light and free will.