To be fair, you can get success more easily in US if you have connections which is the same as China. Maybe Bill Gate and his mother's background is a similar example to what you referred about DiDi.
Don't be ridiculous. If it were actually the same, then Bill Gates could have used his influence to get Netscape's site blocked from the internet or depending on the depth of his connections with Bill Clinton at the time, get Marc Andreessen thrown in prison.
But on the other hand, you seldom see people in Silicon Valley are actually from the valley. They are immigrants from different states and countries. They abandoned their connections (especially family connections) from home to start over here. Many of them became successful.
China simply doesn't have the same soil for this kind of success.
For those who do manage to become billionaires, the game often becomes even rougher: http://www.forbes.com/sites/raykwong/2011/07/25/friends-dont...