The research in this area overwhelmingly disagrees with you. The concept of a baseline happiness is very well studied and supported. It's not difficult to search for.

I think you'd probably be surprised if you had billions of dollars how much less happier you would be than you expect. There is a reason billionaires don't act like they're high on heroin 24/7. Money isn't some magical happiness generator that ramps up with every extra dollar available.