Yes.
However, my point is that, although some have more opportunity than others, that opportunity usually is accompanied by higher expectations, both internal and external.
And I don’t feel the need to wipe out “poverty”. Rather, I feel the need to wipe out hunger and disease. There are some very happy poor people and very miserable rich people.
By today’s standards, Laura Ingles’ family (Little House on the Prarie) was destitute. They wouldn’t describe it that way, though.
I completely agree with your point about happiness having an inverse relationship with wealth. That has, with very few exceptions, been my observation with the humans I have known.