Anakin's role in the story is complete, Palpatine is dead but the Republic is not restored, nor is the Jedi Order. The Empire was dealt a death blow but we don't know what happens next. We only see the celebrations at one point in time. We don't know how they started, or what the backlash is afterwards. They might be only celebrating the death of Palpatine and Vader. The fall of the Jedi Order was big in the PT and the after effects of the fall were felt in the OT. Yeah Luke is a Jedi but only 1. The Jedi Order is not back yet. Yeah the future is in good hands but still unsatisfying imo until we get that. If Luke doesn't do it, who will? Why should we care if someone else steps up and does it?