All hell breaks loose. This powerful scene has been parodied, pastiched, and played out over and over again for the last 50 years—and it still holds up today as an enduring piece of cinema. However, no definitive reason has ever been given for why Obi-Wan lets himself be “defeated” on the first Death Star.
Yes he did. And the saddest thing is that there was nothing he could do about it. He was broken. The first case is shortly after ROTS when Vader was making his Sith lightsaber.
He couldn't bring himself to kill Darth Vader, however, because he continues to associate him with the Anakin he trained as a boy. This is also the exact reason why Obi-Wan didn't kill Anakin on Mustafar despite the opportunity a decade earlier in Star Wars: Episode III - Revenge of the Sith.
Darth Vader's crushing defeat at the hands of Obi-Wan Kenobi in the Disney+ series' finale is his worst loss yet in the Star Wars franchise. The following contains spoilers for Obi-Wan Kenobi Season 1, Episode 6, "Part VI," now streaming on Disney+.
He slays Sidious and returns to Obi-Wan, begging for atonement by execution, only to be met with true forgiveness instead. But just as this fantasy Obi-Wan refuses to strike his former friend down, Vader refuses to turn his back on the dark.
Obi-Wan knew it was only a matter of time. So, he made the difficult decision to use his learnings and become one with the force, rather than let Vader decapitate him.
For years, Vader hated Obi-Wan, having been struck down by his mentor and left for dead while also believing the Jedi had worked to turn his true love Padmé against him.
But this epic showdown ended on an incomplete note, with Vader allowing Kenobi to escape with his life as a wall of fire separated the two characters. Not exactly what viewers have come to expect from the ruthless Sith lord.
Firstly, he hasn't fought in years. In order to hide from the Empire, he needed to keep a low profile. This means that he's not in his best fighting form. Couple that with his wavering faith and he isn't really attuned with the Force, further impeding his fighting skills.
Anakin does not have even the slightest bit of remorse. By the end, he feels nothing but anger. Although he feels regret for killing Padme, he still helps the evil Emperor. The film ends with Anakins standing side by side with the man on whose behalf he has committed all his crimes.
Most specifically though, Vader hated the most important person in his life, his son Luke Skywalker. Vader believed that Luke was the only thing standing between him and ultimate power. So, in short, the person Darth Vader hated the most was his own son- Luke Skywalker.
This isn't to say that Mace Windu isn't powerful when it comes to the force. He's on par with Darth Maul and is more powerful than Qui-Gon Jinn. But, Obi-Wan is still the stronger Force user which makes him a powerful combatant.
Darth Sidious was always stronger than Vader, which is why he ruled over him for almost 20 years and turned him into the Sith Lord he was.
Vader responded “I am not your failure, Obi-Wan. You didn't kill Anakin Skywalker. I did.” This allows Obi-Wan to finally accept that Anakin is truly gone and that there was nothing he could have realistically done to save him.
Darth Vader showed no emotion at all when he killed Obi-Wan Kenobi. If you watch the scene carefully, you will see Kenobi pausing. He was letting Vader kill him. Whether Vader knew this at the time, or discovered it later, is an open question.
Why does Obi-Wan Kenobi age like that? Because he's not real, and is a fictional character played by different people. You see, Obi-Wan Kenobi is played by Alec Guinness in the original trilogy. Guinness was 62 when he filmed A New Hope, and he died in 2000.
Anakin admits to Obi-Wan that he has been arrogant and unappreciative of his training, and apologizes to his master. Obi-Wan assures Anakin that he is proud of him, telling him that he has become a "far greater Jedi than I could ever hope to be."
Theory 1: Leia Doesn't Remember Ben Is Obi-Wan
Throughout her encounters with Kenobi in the series, he refers to himself as Ben. The most straightforward explanation would be that Leia knows the person who rescued her is Ben, and never connected the dots that Ben is actually Obi-Wan.
In the annals of Star Wars history, many believe Obi-Wan Kenobi was the key to saving Anakin Skywalker's soul before his fall as Darth Vader. However, as Kenobi's recent Disney+ series showed, that was never really the case. Anakin lost himself to the Dark Side way before Obi-Wan's intervention.
As he turned to the Dark Side and became Darth Vader, Anakin came to hate Obi-Wan, but never stopped respecting him. In the end, it was Vader who would take Obi-Wan's life, but it was Obi-Wan who would set up the path for Anakin to be redeemed.
Darth Vader hates Obi-Wan, not because he blames him for his fall to the Dark Side, but because he turned Padmé against him and destroyed his body.
After defeating Darth Vader in the Obi-Wan Kenobi finale, Obi-Wan broke down and began tearing up when he saw Anakin's scars. It was the first time he had seen Anakin's face since leaving him to burn on Mustafar, and so he apologized for everything that had happened.