Can't replace the thugs before removing their air cover. Why are cops corrupt? Because Judges require their violence to enforce court orders. Always remember it's law en-FORCE-ment.
So why not replace corrupt judges? Oh yeah, because another will just step into their place too. Senators and congress critters at the state level will protect THEIR boot lickers, because, after all, without FORCE their mandates and petty desires go unfulfilled.
This goes all the way to the top. The ONLY way this hell ends is when or if the government is rendered functional and relatively "pure".
Until then nothing changes because the people suffering have no agency and nobody wants to buck a system that rewards evil.
Or society completely implodes, in which case would would suppose that those used to using violence without consequence against others would either become warlords of their areas or dead in short order.