All empirical evidence perfectly contradicts your assertion. A large majority of those living in poverty display a lot more happiness and contentment than the majority of extremely wealthy. How do you explain that? The reason can't be that those in poverty just don't know better because that would imply that the extremely wealthy do know better yet still don't show contentment and display true happiness.
I reckon that the reason is that most in poverty don't have the means nor time to focus on a whole lot of other pursuits than being with family and caring for those dear to their heart. Coincidently that is exactly what truly causes happiness.