The solution is a government made of good people, at least to some extent.
The solution is transparency, each and every time. You can't expect a position of power not to be exploited by bad people unless you make it very difficult to get away with wrongdoing.
Countries with relatively little corruption and crime did not get that way because they're inhabited by superior people. The got like that by having long-standing traditions of distributed power structures. The cultural evolution that you speak of is part of it but it is entirely enabled by the "vertical of power" being low and flat, allowing for checks and balances. If conditions remain that way, it fosters honesty because it is easier to be successful that way. But the risk of backsliding is always there.
transparency is the answer.
Hold everyone to account, from the grassroots up...
A lot of the problems we see today, would never even have had the chance to develop, with openness in the system.
Very good point.