Most humans (except maybe Buddhists and Daoists) are on a hedonic treadmill. So long as their condition today is better than it was yesterday, they generally derive greater contentment than being better off in absolute terms and then plateauing.
This "most people were better off over time" is the stuff stable societies are made of. It's why post WWII America did so well. It's why China has been doing well for 20-30 years now. When most everyone is doing better today than yesterday and believes they will be doing better tomorrow than today, they are content.
Even poverty is tolerable if things are improving over time because you adjust your expectations.
The lack of improvement over time is what makes prisons for example such an awful punishment. You're placed in a state where your conditions are not only worse in absolute terms but there is no prospect of it really improving until your really.