The Jedi Order always implodes due to the council gradually becoming terrified that their knights will fall to the dark side and turning draconian. Someone rebels and takes the whole thing down, usually with Sith help. The survivors get a much healthier world view, then eventually rebuild the Order in a more enlightened manner. Then the Order decays and implodes again. The Jedi seem to be at their best as a philosophy rather than as an organization.

That seems to me like it’s one of the themes of the series: the Jedi order, though it had good intentions, had lost its way due to overly rigid structures and beliefs, to the point where the Sith were able to take control of the Senate and Republic that the Jedi swore to protect right under their noses. And their rigidity ended up driving the chosen one to destroying them before destroying the Sith (though in actually just weakening both).

Dooku left the Jedi for a good reason. Palpatine wasn’t the answer Dooku thought he was, but Dooku saw first-hand the evil that the Jedi were enabling and even enforcing since they didn’t consider loyalty any deeper than “are they an elected leader?” and placed more importance on following rules than doing the right thing.