It's addiction.

Simple as that.

Just like a crackhead or a heroin junkie can do whatever crazy shit a non-addict would never even think of, so do the rich billionaire money-addicts.

Just look at the difference between CEO's and mega-class actors. Lots of actors can be addicts, yeah, but not many of them are that addicted to money, and while they might buy things we consider ridiculous, they're not actively ruining society, just benefitting from capitalism.

Whereas people like Bezos are addicted to money and actively ruining the world. He could lose 99% of his wealth and still live the same, barely fucking notice a thing in his quality of life.

NYTimes sucks and I don't link them anymore but for thus exception as an opinion piece from Sam Polk.

https://www.nytimes.com/2014/01/19/opinion/sunday/for-the-love-of-money.html

He wrote a whole book about it

https://www.goodreads.com/book/show/27274419-for-the-love-of-money