HAPPINESS
(One definition–and I’m sure there are many more)
“Happiness is a mental or emotional state of well-being defined by positive or pleasant emotions ranging from contentment to intense joy.”
Wikipedia

I agree that you can’t assume people with either more or less wealth have either more or less happiness. That generalization applies both ways.

We, and most people we know don’t consider money the source of our happiness. Sure, we’re all grateful to have the funds we need for ourselves and our kids for the balance of our lives, which may give a sense of peace and security–but, imo, true happiness–to the various extent that each of us experience it–comes from far deeper and more meaningful things in our lives.