GDP is not an accurate measurement of per-capita wealth. Just for example, let's take the US steel industry. US and India produce similar amount of steel, but US only requires 1/5th as many workers, so the average productivity of a US worker is 5 times more, even though both contribute a similar amount to GDP. That's why the wealth of an individual American is more. This factor also applies to everything else, agriculture for example, the average American agricultural worker is 10 times more productive than their Indian counterpart. Average US car factory worker is 7 times more productive etc.
The vast majority of global south productivity is actually in China, which is already industrialized and considerably wealthy compared to other global south. Countries like Pakistan or Dominican Republic or Peru or East Timor are poor mainly because of low productivity.
But they have to pay interest, so its not really unlimited money