Simply physical comforts will not make humans happy.
We have very intense cheating detection, perceived inequality, unfairness or injustice will piss us off.
Also, our evaluation of how well-off we are is based on comparing to our neighbours.
True - although it's often a very mono-directional detector. Anyone higher up on the ladder, or taking advantage of cheats we didn't see, gets the full focus of our attention, while anyone lower down or slow on the take is clearly just a sucker.
Pretty bad heuristic, unfortunately.
Correct. But take away "physical comforts" and people are much much more likely to be unhappy.