Some fans think Palpatine’s return in Rise of Skywalker negated Anakin Skywalker’s sacrifice in Return of the Jedi, but I completely disagree. Let us not forget that Palpatine returned in Legends and no one seemed to complain. Also, after Palpatine’s final death, the Sith returned three or four times in Legends ranging from Lumiya’s Sith, the Lost Tribe of Sith, and the One Sith. Who knows? The Sith might return again sometime after Rise of Skywalker in the new Canon. The Prophecy of the Chosen One did not say if the Sith would be destroyed permanently nor did it say how long the balance in the Force would last. As far as I’m concerned, Anakin fulfilled the prophecy even if it was for a brief time.