It doesnt destroy the content, but it weakens the parts that are corrupt.
Say that the ruler installs his brother as the head of emergency response, and then his brother spends most of the money on jet skis and cocaine instead of emergency preparedness. Everything is fine until an earthquake hits, and then the country has no rescue equipment and nobody actually qualified to run the response.
This can lead to especially bad situations with the police and military, and if they become corrupt enough then criminals can essentially take over. Want to run a store, or a restaurant? Make sure to pay (bribe) the local crime syndicate or else they’ll burn your place down.
If enough pieces become thoroughly corrupted, the government basically loses control entirely and you end up with criminals / militias / similar groups running everything from law enforcement to schools, eg the taliban and ISIS, or just terrorizing the people for their own profit.
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