People want to be needed, instead we have become isolated individuals that need no one in particular.
Depression then also happens among rich people. But the source, and expression of it might differ. An anecdotal saying explains that wealth is often a barrier to create true friendships because it insulates you from society and creates antisocial thought processes: the "thinking people just want to be your friend because you're rich" rhetoric.
I'm not rooting for Marxism exactly. I think it is an extreme overcorrection, but that some correction has been and is still warranted at times, given regulatory capture and other abuses that come from concentration of power. Anti-trust action and semi-effective democracy/representation are needed.
I think we are in a society with solutions to almost every problem except for those that require cooperation on the scale we exist at, which is unprecedented.
I sympathise with the idea of mindless hard labor being more fulfilling. Working food service in the backroom as a teenager worked my body but left me less stressed mentally than anything I've done post-graduation.
Don't all those rich people also get depression? I think that rules out a marxist reading here.
If you're going to go this general direction, i'd say a better way would be, we now live in a system where work is never done, stress is pretty constant, and labour is less physical but more mental in the modern world. Perhaps our mind is just not made for continous mental labour. Being a farmer in pre modern times sucked, but at least you could turn your brain off more often.