I think it's way late to start talking about that. In America, we have this puritanical ideal that working leads to happiness— or that working is, itself, happiness. Scientifically speaking, that's bollocks. To take the classic case study, people who win the lottery aren't any happier or unhappier than their workaday peers. They are exactly as happy.
Real happiness seems to come from something like the Buddhist ideas of mindfulness and acceptance, and that's true whether you're a poverty-sworn monk, a janitor, a CEO, or a pot-smoking layabout.
The idea of "rewarding work" vs. "empty hedonism" is an arbitrary Western construct with little basis in reality.
Forgive me if I've misread, but I think what you're putting forth as acknowledged fact here is in fact controversial. You seem to be referencing the 1978 study "Lottery Winners and Accident Victims: Is Happiness Relative?" as well as, perhaps, the idea of the Hedonic Treadmill. Brickman's ideas are considered outdated.
That's not to say that working, alone, producing happiness is a correct idea, but it might make sense that accomplishment does. And these levels of accomplishment - cleaning the floor well for a janitor, for instance - can differ. Most people desire to "make a difference," another way of saying the same thing. If you're talking about deathbed wishes when looking back on a life, the more positive impact your life visited on others, the better.