Like the games that we play on Facebook will start accepting payments in Libra and all the other money dealings will be actually carried out with the help of Facebooks very own digital currency. The bill will be passed. The coin is highly centralized and utilizing it does not make sense at all. Anyone who loves his freedom and privacy, will invest in bitcoin or ethereum. But this kind is again a rare one.
Even if they accept Libra, they will be accepting the other payment modes as well (such as PayPal, Visa, Master.etc). So my question is how they will make the users prefer Libra over the other options? Libra is a new payment method and at least initially the vast majority of the users may not be comfortable in using it. So unless they give some good promotional offers, no one is going to use Libra.
If they are creating their won coin for their payment system for facebook then it means that they will not accept other coins or payment processors for facebook. Or if they will accept other payment processors or bank cards then it will mean that they will choose other payment processors and banks for fiat users and their Libra for crypto users.