I learnt that economic output it what makes a nation prosperous. So producers are encouraged. And money supply expands relatively do to extra output... but If that's the case, does that mean anyone who is producing a decent resource will earn wealth? And if so, then how come everyone can't be rich

My only thesis to this is that people can work to increase their standard of life. But the term "rich" is relative so even though some one can increase their living standard a great deal. Some one will always have more than them... Am I correct?