One word comes to mind and that's "Attention". Not all of rich people of course, as many rich people rather stay away from spotlight because they have better things to do with their lives, but these days attention is easy to get, and it is addicting.
Not every billionaire chooses to rant in public, but they will give interviews and ted talks, because rich people have always fascinated the audience. Especially eccentric rich people, as people relate to them. Not because they themselves are rich, but because they are imagining what it would like to be rich.
But ask any rich person if money takes away all your problems and you'll hear the same answer: no. It only provides financial security, because you don't need to be afraid if you can afford to eat next week.
It brings lots of responsibility, and richer you'll get, more you want to spend that money to hire more people doing things for you. People taking care of your houses, people guarding you, team doing your taxes. And suddenly you are responsible of lot of people. That can both make you a cruel person, that wants to toy people around you, or appreciating people around you.
You will still have same problems with relationships. Same insecurities if you haven't worked on them, and you will probably compensate a lot with fancy cars and money.
And at some point being rich can become part of your identity. Then you want to make sure you take care of that identity, and losing your money would be similar to losing yourself and that feels like dying. Many rich people are on therapy and their families too, not because they would have failed on life, but because dealing with your problems to be a better partner, dad or a fried is something people want to be.
And no matter how rich you are, you will eventually die, or everyone you knew around you will die, and you will have to suffer like everyone else. That's sad, and normal part of being a human. No matter if you are rich or poor.