If you are talking about major institutions, they usually develop for legitimate reasons. All major institutions are exposed to the greed and corruption of people.
But, generally, getting rid of them entirely is usually much worse than keeping an imperfect institution around.
If you are talking about local government, if local citizens really get involved in local government, they usually can have a profound impact, much much more so than on a state of federal level.
Why not consolidate local government into federal?
Generally, diversification allows for more independent control. So, if the federal government is excellent, then you get better services to local communities. But if the federal government is bad, the local communities get horrible service.
So, it is like hedging your bets against potential corruption.
Dr. Benjamin Barber wrote a book about using the power of local government to help change things and stop corruption.
https://www.amazon.com/If-Mayors-Ruled-World-Dysfunctional/dp/030016467X
(he was a professor at Rutgers University, here in NJ)