Star Wars: The Clone Wars served as an important continuation of the stories George Lucas set up in the prequel movies. The animated series was embraced by fans, and it would have been hard for any follow-up show to live up to what The Clone Wars did, but Star Wars: Rebels proved to be more than capable of taking on that challenge. Just as Clone Wars helped fill in the past, everything that has come after Rebels has been directly impacted by many of the events that occurred in the show - including the currently-running Ahsoka.
Source：https://www.cbr.com/star-wars-rebels-importance/
