Coin Libra is distinguished by a large set of ordinary currencies and even various securities of business structures that will provide this coin, as well as the fact that it is behind such a large social network like Facebook.
In my opinion, confidence in a stable coin will be greater if it is issued by a state or a group of states. Zuckerberg may go bankrupt and then his Libra will become worthless. This is unlikely if the credibility and the economic power of the state stand behind a stable coin.