Yes. We have the voting system in the DAO. I am a diplomatic nerd and believe me when I say that you cannot just combine the two systems that is the UN and the DAO as they are currently and you think that it will work. It is bound to be a big failure because:
1) There are so many special interests right now in the UN that would not even consider the DAO. There will be a lot of resistance if the idea to just join the 2 was placed on the table because many are benefitting from the system.
2) The veto power of the UN security council will completely negate the whole idea. The only thing you will achieve by combining the two now is a better voting system but as long as the veto power remains, the system will still be controlled by the few and you will not have changed anything.
3) The current structure of the UN is not compatible with the DAO and it really isnot intended to achieve the same goals as the DAO. Yes, it is meant to bring about cooperation but in the UN system that collaboration is meant to be spear headed by the few. THe DAO is decentralised and everyone has a say in what the results will be. In the UN, only the Security Council, the victors of WW2, control the outcome and with their veto can decide or fail to change things.
With the few reasons I have given you clearly see that if the UN is to ever be decentalised it has to undergo some serious change. It must be first remodeled or else it is a losing battle.
And lastly, I am not talking about everyone making profit from the UN if it functions as the DAO. NO, quite the opposite. My idea is that as a citizen of the World, that should entitle you to one vote in a much more decentralized UN system. Its not about making profit at all but bringing about change. However, the system needs to raise money to meet its goals like improving health care and reducing poverty so a decentralized system in my view would be much better at raising these funds for the organization than the current system where only a few nations provide any significant funding for the UN.