When a country gains more monetary wealth than it has had in the past, there are two paths that it can take. One is known as economic growth - of money being invested into producing real wealth; the path taken by America and England during Industrialization. The other is known as inflation - of the money losing its value, things becoming more and more expensive, and the gain being squandered - the path taken for example by Spain after it was inundated with gold from Mesoamerica.
The same applies in human happiness. When state of affairs of any person improves, the two paths possible are happiness growth and expectation inflation.
In the first case, the person joyfully embraces the improvements and becomes a happier person. Remaining grateful and appreciative for what he has that he did not have previously, he exists in a happier mindstate. Any new improvements are likewise met joyfully and appreciatively. And the improvements are never taken for granted, but are appreciated in each case, resulting in ever greater happiness of the person.
In the case of expectation inflation, the person takes the new state of affairs for granted and begins to expects it. Instead of becoming happier, he requires more and more positive conditions to sustain the basic mental state. Sense of entitlement grows, requiring more and more to meet ever-growing expectations and making happiness ever more remote. The improvements are inflated away to feed the growing expectations. The demand grows out of control, necessities grow beyond all measure, and more is required to sustain basic level and more still for any level of happiness.
Both phenomena take place at the individual level as well as the collective. The current state of existence of most people in the First World would have been unthinkable to most people in history; and yet many take it for granted. Frequently it becomes worthwhile to show such people how life is elsewhere and how it has been before they have sufficient appreciation to value the life that they have and the efforts of hundreds of millions of people who made it possible. Only then - when the overly-inflated expectations are shown for the folly that they are - can people develop the appreciative state of mind that is required for actual happiness. It is then that happiness can grow. And then these same people can become contributors to happiness of their families and of their country.
For happiness of people at both individual and collective level, it is necessary to encourage happiness growth and confront expectation inflation. In this the good is not wasted but is appreciated, and is affectuated improvement both in human condition and in people's experience of life. And then it in fact becomes a worthwhile endeavor to put in work to improve human condition, knowing that it will not be taken for granted but rather benefit people, and will not be inflated away into bloated sense of entitlement but rather lead to happiness in people who live and are yet to live.