Most adults agree that money will not make us happy yet we would almost all accept more money if offered.
I use "adults" to mean not a chronological period which a person has exceeded in age, but a point at which each of us matures to understand the most important things in life. There are plenty of 20 or 30-somethings (and older) who believe that more money means more stuff means more happiness.
I guess my meaning of the word, "adult" is best characterized by a saying which I first heard from John Wooden. He said, "It's what you learn after you know it all that's important." So I guess the point at which each of us no longer believes that we know it all is when we reach adulthood.
But anyway . . . back to money and happiness.
There have been a spate of studies in recent years trying to quantify happiness and although they rely on self-reporting (there being no as yet objective way to measure happiness) they are reported and evidently trusted. Some of them deal with wealth and happiness and it seems that below a certain income level or economic standard of living, each additional increase in money does lead to greater happiness. But this level is fairly modest (by U.S. economic standards) at around $40,000 per year. I realize that a lot of people live on less than that but plenty of those who make more still believe that increasing their salary will lead to greater happiness.
And the evidence just doesn't support it.