The UN is a welfare organization for international busybodies who enjoy their apartments, expense accounts, and the nightlife of mid-town Manhattan. If there were no UN they might be forced to return to their own countries where there are no jobs, nightlife, or expense accounts.
I am convinced that is really what the UN is about.
Plus they can park their cars wherever they want without fear of a ticket.
You seem to have forgotten about the incredible opportunity to take bribes from dictators.