There are many cryptos pegged to the dollar, I like the project DAI, but most used is USDT. IMO read the original white paper, it explains the problem with previous centralized attempts before Bitcoin came along and found a first solution to the Byzantine General’s Problem.I'm not doubting that, what I am saying it there are other possible solutions.
For example, a new coin could have a base peg to the US dollar, that means there is an iron clad guarantee that coin is worth at least one US dollar.
I don't the the UN and the world bank, backed by the international banking system, would have any trouble convincing people their coin was valuable, I would buy it.