During his exile on Tatooine, Obi-Wan often repeated a promise to himself, one that he found harder and harder to stick to.
He promised that he wouldn’t interfere with events on the planet.
He had one goal… to protect Luke from the Empire and the boy’s father, Darth Vader. If Obi-Wan ever interfered with the local thugs or Hutt’s operations, then he risked outing himself as a Jedi, and eventually that would draw the eye of Darth Vader. It would only take a steps for Vader to realize Obi-Wan was on this planet protecting someone… Obi-Wan couldn’t allow it.
No matter how difficult, and painful it was to watch the innocents of Tattooine bullied, beaten, and killed by ruffians, Obi-Wan mostly stuck to his oath.