My interpretation of the Final Scene
Contrary to the analysis of reviewers and most people in this forum, I believe the ending is one of optimism, not despair. Bob Dylan entering the scene, and revolutionizing popular music in the process, provided a huge opportunity for those musicians lucky enough to already be a part of that scene.
Let’s keep in mind that –at least up to that point- Llewyn did not have the brilliance or charisma required to successfully run a solo act, much less a movement. Perhaps Bob would become the “partner” that Bud Grossman recommended for him, and this partnership would bring out the best in Llewyn. Remember that the real Bob Dylan was friends with Dave Van Ronk, and both collaborated quite heavily in the early days. Would Van Ronk (as talented as he was) have enjoyed the same success without Dylan? I do not think so.
Even if Llewyn does not become as successful as Dylan (which was never his intention, as that would have been “careerist”), he would still make a decent living off music. Consider that, back in the 60s & 70s, well-known artists could make really good money off records & royalties. Most importantly, Llewyn would be in control of his future, doing what he was destined to do, and not simply “existing”.
Reviewers tend to focus on how the final scene somehow brings Llewyn back to his starting point. I disagree and, further, I don’t think this event is relevant at all, considering that it did not affect his superb performance* that night, or his upcoming review in Time magazine. The man in the suit will be gone and never to be seen again in NYC. With that said, it’s very unlikely that this beating will set back Llewyn in any significant way.
* Regarding that performance, I really do think that it represents a turning point for Llewyn. That version of “Dink’s Song” (sung in a higher key and with significantly more intensity than the previous two versions of that song in the film) was beautifully delivered, and with far more passion than Bob Dylan’s version of “Farewell”. Would this be the moment where he starts “connecting with people” and turning his life around?