I would imagine any divorce after that long being married would be tough to accept, remaining a billionaire after the divorce is not a bad way to end things with a spouse.
When she married Bill Gates he was a very wealthy tech nerd who founded Microsoft, with all that money and the people he was exposed to, he became a pervert and began to believe his own hype.
As a business associate from a former life put it “Money may not buy happiness, but it sure as h3ll can cover up a lot of misery.”