The folk revival kept the sound -- the instrumentation and acoustic sensibility -- alive for a generation of creative people who had a better idea of what to do with those tools to create art with them (rather than simply keeping alive a tradition).

So, even though the music of the folk revival was very un-creative (by definition), it kept a certain sound alive for people like Stephen Stills, James Taylor, Jim Croce, Gordon Lightfoot, Don McLean, and others to use to express their creative genius.