This quote, from Richard Feynmen, is so powerful it, caused Herman Wouk to write a book to address it. I am neither a writer nor a scientist so I won’t write a book, but as a student of Judaism I write the following short point.
Yes, if the purpose of creation is merely for “G-d to watch the human being struggle for good and evil” then perhaps Feinman has a point; but, like so many others, this great scientist failed to discover the depth of the religious position.
The Kabbalh gives two reasons for creation: the second reason is in order for the Human being to “create a dwelling place for Hashem in the lowest realm”, this, in other words, is what Feinman calls the struggle with good and evil. The Kabbalah, however, also offers another reason for G-d creating the world: “so that they will know him”, meaning that before creation there is nobody to appreciate G-d’s greatness. He wants to be known. So he creates a universe to so there will be a being outside himself to know him.
In order to help a finite being to “know” and fathom an infinite G-d, for the creation to understand that the creator is beyond anything in can comprehend, G-d creates a universe too vast for the human mind to grasp, to serve as a parable for G-d's infinity.
[Perhaps we can argue that both reasons for the creation are in fact two sides of the same coin: in order for the Human being to understand that he was created with a mission bring good to this world (the first reason) he must realize that there is a creator, a creator that is infinity and unknowable, a glimpse of his greatness is knowable from the universe (the second reason)].
So yes, the drama absolutely requires a great stage. For without the vast stage the actors may forget about the author and drop the drama mid play.