You push a narrative by including 'western' there. Non western nations also have tremendous wealth inequality.

You are also pushing a narrative. You can't ignore the basis of the hypocrisy of the west: the west purports to be better. You aren't just not doing better than the comment above, you're doing worse.

Why do you think wealth inequality is an inherent sign of corruption?

Because wealth can be turned into power.

Because when power is unevenly distributed a few people can make boneheaded decisions that create misery for the many.

To point to the Russian experience the Tsar made the bad decision to take an odyssey the long way around Asia (and Africa for some ships) to attack Japan and they got their asses handed to them in a few hours. That was the first time Lenin and company tried a revolution and ultimately they made this feature film about it

https://en.wikipedia.org/wiki/Battleship_Potemkin

A few months back we had the spectacle of Elon Musk possibly buying Twitter (maybe he was in the running for asshole-in-chief) but I think he got some sense scared into him and he is keeping his head down these days.

Btw, you still didn't answer the question.

Yes wealth can be turned into power, but you know what already is power? Political power. Wealth is a counterpoint to political power. This is why communist systems become authoritarian, because there is no counterpoint to the power of the politburo. View xi’s crackdown on tech in China as a elimination of a potential competitor, just like his earlier corruption purges.

Show me please how wealth inequality implies corruption.

It's been studied quite a few times and links have been identified. Here is one from 2004.

https://scholar.google.co.uk/scholar_url?url=http://web.hks....

This particular study is just measuring correlation. Sorry, this doesn't count. We were talking about inequality CAUSING corruption.

Well, okay corrupt, but still capable of self-repair. meanwhile others have the corruption build into the very system of thiefdoms handed out to nobles.

Also there are quite alot of ideals at work, for example when it comes to free trade. Anybody can sell his product and ideas in the us, meanwhile alot of beligerents, have walled of their societies from free discours and sabotage any external market contenders.