The Jedi are not a bad thing. But perhaps their day is done. 25,000 years or whatever is a good run. But even they got too wrapped up in traditions and such. They lost what they were, and they can't bring it back. So it might be time to move on. Let the next thing come and reshape how the Galaxy views the Force. The Jedi Order fell nearly 55 years ago for the Galaxy by the time of the Rise of Skywalker. There have been a few beats here and there over the decades from survivors and trainees of survivors. But for the most part, it was gone as far at the public was concerned. Luke Skywalker was basically the last legend of a Jedi Knight for most. It is unclear if there are rumors of Rey floating around, of if the last set of legends are Luke's stand on Crait.
Similarly, Palpatine is the last Sith. Snoke doesn't seem to have been a proper one (if he was one at all). Darth Vader turned again at the end. If Palpatine's still around, than the last Sith must fall to the Skywalker (prophecies are weird sometimes)
Rey managed to either make her own lightsaber, based on Anakin's, or she rebuilt Anakin's lightsaber from the parts she had left (though the one she has looks like it fits her hand better than Anakin's did). But there is a LOT of missing plot here since we only have a teaser. The Saga ends, but a new legend is crafted for a new generation.
