I would argue that reading Moby Dick is of value to your quality of life in general. Good fiction speaks to the human condition and can help us live our lives more fully.
And it makes things richer just in your daily life to have some familiarity with history and the literary canon instead of being deaf to its influence all around you.
I will respectfully disagree that it leads to a more 'full life' for everyone. People have different perspectives, values, etc. and that type of experience is purely subjective. I personally think it's of some value, but not as much as some other content.
