During Ahsoka's trial, Bariss Offee called the Jedi Order "an army fighting for the dark side" and said they have all "fallen from the light" they "once held so dear". In Rebels, Yoda agreed with Bariss and told Ezra that the Jedi were "consumed" by the dark side during the Clone Wars.

This is prequel stuff, the Jedi didn't fall because they were dogmatists obsessed with the light, quite the opposite in fact. They fell because they compromised their ideals in the name of pragmatism, and that is actually the philosophy of the Sith, as Palpatine himself told Anakin in Episode III. The Jedi are supposed to serve the will of the Force.

Now, it always bugged me that in Season 6 of The Clone Wars it seemed to me like Palpatine had an ungodly amount of luck given how close the Jedi Council got to ruining his plans, but recently I remembered that there is no such thing as luck in Star Wars. What is called luck, that is often the Force guiding events. And it's the Cosmic Force in particular.

So... was it the case that the Cosmic Force gave up on the Jedi because they gave up on serving the light? In that case, Palpatine's luck in Season 6 was more driven by the fact that "luck" itself [the Force] abandoned the Jedi.

Theory from redditor u/persistentInquiry