In my experience, extreme wealth is a sign of one or more of: inherited wealth, lack of morality, lack of empathy, lack of humility, lack of self-reflection, or luck. In most cases these people are simply so broken that they’ll justify exploiting other people to get what they want in ways that people with morals simply refuse to.

Intelligence isn’t a major factor.

Also they’re willing to spend millions of dollars on a dinner like this because what’s the downside? Losing that money won’t affect their lifestyle in any way. Worst-case scenario, they get a story out of it. Best-case scenario, they get face time with the most powerful person on the planet and maybe a sympathetic ear if they get in trouble with the law (since all of them are privately breaking the law in some way).