UN organisations are sponsored by Billionairs and not financed against nations by rich men.
The UN has several bodies called organisations to deal among nations as a nutral partner from economic to coltoural to criminal affairs. That needs staff, offices, communication and transport on top of good will.
All that needs money, except of good will.
In a world in which humans are rich due to ruling corporations and in which money is power, more money means more power.
In a world in which good will can do a lot of good it needs a good position to live that good will.
Currently, and this is about to change, only nations and rebells use force as arguments in negotations. Most of the time all, nations, rebells, corporations and charity organisations use money to act. They either give or take.
As a matter of fact some nations, including the U.S. Governement, regularely do not pay their agreed dues to the UN, who will have to cut down on any of staff, offices, communication or transport making the good will suffer as a side effect.
The enemy of my enemy is my friend is an old simple rule and the corporates biggest enemy is the nation coming with regulations, taxes and force.
Guess why rich men pay money to the UN instead of hiring gun men?