Through rewatching the saga over and over I find it endlessly fun and fascinating to identify all the causes and effects in the saga. For example Han Solo ultimately failing to keep Leia safe in Empire is why Luke is lured into a trap on Bespin and finds out Vader is his father which then leads to him seeing the good in him and trying to redeem him in ROTJ. Thus the asteroid chase and Han evading the Empire in the Falcon only to be eventually caught because he exhausts all options and has to trust a shifty friend in Lando is why the saga unfolds the way it does. Also Boba Fett playing a role in tracking the Falcon to bespin. Boba Fett who became a bounty hunter and hated Jedi since his father was killed by one in the battle of geonosis. Another is Han getting involved in this saga at all. Obi Wan just needed someone to smuggle them off Tatooine to Alderaan and Han is taking this job because he owes Jabba. This one simple transport job ends up changing his life forever. The reason he ends up where he is at the end of force awakens is because he took this one job. Let us not forget the whole saga started because Qui Gon and Obi Wan were sent to settle a trade dispute and end up on a diversion to Tatooine that sets in motion the entire Skywalker story.