Be careful of falling into the exceptionalist trap (my culture is special, we don't do corruption), or the natural progress fallacy (you have to be corrupt and warmonger first, then you grow up, mature and become a stable and moral democracy, it's the way it happens). Both are false premises that stem from cultural hegemony. There's plenty of corruption (lobbying is a form of legal bribery too), and instability in the developed western world. The US survived a coup attempt just a few years ago. Lots of officials and politicians are caught stealing public funds every year.

The difference lies in the narrative lens. When it happens to the west it's "a few bad apples", or a lone bad actor. When it happens in the developing world it's that filthy culture struggling to become as civilized and democratic as us. It's the pure expression of neo colonialism. The real material difference is that the West has accumulated more wealth for longer. And they control the mass media machinery.

Because developed countries already went through their corruption. The processes by which these countries became democracies tend to be bloody. Other countries were behind the curve, then their political and social development was frozen in time by Western colonialism.