If indeed Libra is a stable crypto currency then this is indeed a safe thing for Libra in the exchange of crypto currencies, so if Facebook aims to create a central bank of the currency then I think it will work.
It will work for sure, but will you use it? We are trying to run away from the broken banking system, at least most of us want changes, what`s the point in creating the central crypto bank? For me, the choice is in front of us is simple, we can choose to continue with the centralized system in crypto form, or to pursue decentralization. I made my choice a long time ago, and I`m one of the people that will not use Libra coin, I`m sure in that.