The #1 problem with this is the obvious prequel problem. We know where the story starts and exactly where it ends. There's zero tension. Spoiler alert! Obi Wan is going to make it out ok. While it is fun to see more of Vader and Obi Wan, it still has nothing behind it. Star Wars is never great on deep characters, so once you take any suspense out of it, you get this. It is always going to leave us hanging, because we know exactly how this story ends, and it doesn't end in this show.