It’s weird that you would assume something incorrect like that, when you can just google it and find that the money was
the reserves of Afghanistan’s commercial banks and ordinary people’s savings
It’s literally the business and personal savings of the Afghani people, inaccessible to them for over 2 years now.
Even if your cartoonish depiction of the Taliban was true, it is not a good justification for the US to freeze all of the bank accounts in Afghanistan.