Well, the most obvious value to me is that you can create algorithms that defer their action- So instead of having a function that operates on a collection, you can have a function that will operate on a collection at a future date, even if the collection does not yet exist. (that's what the clojure reducer library does)

(And if you say "deferring an action is just another term for 'functions'" then that's exactly the point, lifting more algorithmic logic into composable functions)