To put it by comparison: Monaco (the country) is a smaller than Central Park in NYC but their GDP per capita is around $256,000 while the USA it hovers at around $92,000. Like why does a European microstate that small have a higher GDP than a major super power? They don’t have income tax to be worried about (unless you are a French citizen).
Is it because everyone there is basically a millionaire or working in the tourism industry where their main clientele are basically elites who have left over cash? The country’s population is 38,500 (about half of San Clemente, CA) but even with a small population, do people in Monaco have a higher disposable income when you take it into account?
Monaco is a tax haven where lots and lots of companies are nominally registered, so everything they make counts towards Monacos GDP. Since not a lot of people live there, the GDP per citizen is very high, even though the citizens aren’t the ones creating the value.
It’s just a statistical error, similar to the one that causes the Vatican to have by far the highest crime rate in the world (because it has millions of visitors whose crimes are counted in relation to the ~400 residents in the statistic).