These kinds of statistics are so bogus because they make it sound like accumulated wealth is what makes the world go around, and that is just simply untrue. All of this accumulated wealth by the ultra rich, $8.7 trillion held by billionaires, is NOTHING when you compare it to the world GDP PER YEAR, which is $80 trillion. Remember, you're comparing the total accumulated wealth, built up over many years and decades, of the ultra rich with what the global economy produces in income IN A SINGLE YEAR.
For the majority of people, and especially young people, their most important asset is not how much wealth they have accumulated but their ability to produce income year after year through their productivity. And you can't be pushing government pension and welfare programs on the one hand, which incentivize spending all of your income instead of saving it, and then touting stored-wealth as the important statistic.
Through the worldview of this ridiculous methodology, graduates of elite American universities, with their high paying jobs but substantial student loans, are among the poorest in the world. Ditto for the highly-paid San Francisco software engineer who spends most all of his income to live a very comfortable life in one of the most expensive cities in the world. Better start transferring wealth to them from the bank accounts of middle class third-worlders!