One good way of measuring economic success is by ignoring the income and wealth of the top 10%. The exact percentage is not important. What matters is the idea that the success of the well-off only benefits the society to the extent it improves the lives of ordinary people.

Many government activities make sense from that perspective. By redistributing money from the top 10% to the bottom 90%, they increase the economic success of the country, though possibly at the expense of economic output.

And fairness is also important, because societies are built on trust. When people don't trust government institutions and each other, everything starts falling apart.