I mean that money will be spent in exchange for goods and services that provide salaries and retirement opportunities for more people. It’s not like he’s just hoarding that money, it can’t be used without benefiting other people once he does
The money that isn't spent on consumer goods/services will be invested, where other people can spend that on goods/services, with an expectation of returns on investment, incentivising efficient choices. Economies are cool!
The same would be true if we taxed the money and the government spent it. Right?