I think that his biggest achievement was assimilating the cadences of the beat poets and welding them to those loose, associative, lyrics. The amalgam produced was more than the sum of it's parts. If you are not old enough, have a listen to Ginsberg, for instance, reading his work and you will hear where Dylan cribbed.
It had the quality of being unique while still paying homage to the movement that was so much a part of the day. We used to actually go to the Village just to hear Ginsberg read "Howl" in that inimitable style that, in the final analysis, Dylan actually did imitate.