The U.S. continues to have the largest economy with the largest private sectors introducing new innovation into various markets which is another metric to measure. Current median household income in the U.S. is around 60k USD which isn't much but the U.S has an overwhelmingly high standard of living which reached its peak in 2017, a decade high. Low birthrates just means there are more virgins around
I kind of disagree here.
A birthrate lower then 2.1 will decreases the population and if we dont reverse that we will die out in the long term.
A good economic system should not only increase the standard of life, but also increase or stabilize the amount of population.
But "we" never die out! Why not? Because each person dies for himself/herself. Other people might die at the same time - or real close to the same time. But people don't die together. Each person only experiences death for himself.
Since people usually live to less than 100 years, and since people only die for themselves, there is no "we." If the whole race of humans dies out, who cares? Everybody is going to die anyway. And once you're dead, the rest of the people that are still alive don't matter to you any longer in any way. So, really, the rest of the people barely matter to you even while you are alive. They only matter to you regarding YOUR ease and comfort of living.
What is your comfort and ease of living? Fresh air to breathe, Enough good food to eat. Fresh, clean water to drink. Sufficient clean clothing. Roof overhead that doesn't leak. Friends. Peace. Salvation for Heaven.
When capitalism increases in a person's life so that he has more than this^^, it starts to take away from his comfort. It might even take away from his salvation. And salvation loss means comfort loss for eternity.