This money (US taxpayer money) often just goes to the crony classes within these countries. Those positioned to take advantage of the USA’s largess do well. The “people” often do less well. Especially when considering that much of this money goes to arms. (American arms.)
When it comes to military aid both the Military Industrial Complex lobbyists and the lobbyists of favored countries team up to make sure American taxpayers continue to pay the bills for their clients.