The very wealthy typically invest ... everything? So this means more investments in new businesses and projects and research, and ofc those new businesses and projects and research needs workers who get paid.
Unfortunately lobbying and other sicko greed happens as more money goes to many of those people. Most of those people prefer money that is printed out of thin air anyway
Even so, who's to say they invest it in something sustainable? This is how slums are made: rush from the countryside to cities because "there are jobs" - ten years later the companies go bankrupt and the people are stranded because they sold their farms to move to the city.