We will see where the governments align themselves with creating their own tokens versus using the Ripple platform to transfer existing currencies, but XRP's involvement would undoubtably be a considerable option considering xRapid is one of 3 of Ripples biggest offerings. The whole cost saving ability to Ripples services is based on the XRP token itself.
So how would XRP not be of any value? You do understand how Ripple works right? -
https://ripple.com/ripplenet/source-liquidity/
Again, American Express testing xRapid tech -
https://theindependentrepublic.com/2018/08/27/interest-american-express-proof-ripple-future/
They are already using the xCurrent platform, XRP is the token that when traded through xCurrent creates the xRapid process. Theres no way to use xRapid WITHOUT XRP. See where the value in XRP is? Ripple is selling a system. You think they don't want their customers to use every product that they offer if it isn't a perfect fit for their customer? You think Apple is going to sell you a Mac WITHOUT Mac OS? Without the dongle? Without iCloud? Why would they offer the xCurrent platform and then leave their customers to use some other tech to handle the liquidity? When they can just use the xRapid platform based on the XRP token?
What are they going to use instead?
Moneygram piloting xRapid -
XRP is more than a currency. In fact, its intended use isn't to be a currency at all... To your example, someone could send USDC to another currency and XRP would be the exchange platform used to convert the value. It wouldn't be the currency who's value is being converted.
You don't pay someone in XRP like you would Bitcoin or LTC or any other "currency"
That is what half of the crypto community doesn't understand, or is refusing to understand about XRP. Hence why it has such a high supply. Its not a form of payment, the tokens are supposed ot be used for billions of transactions, they aren't supposed to be the value of the transactions themselves.
XRP wasn't made to replace the dollar. Bitcoin was made to replace the dollar. XRP was made to send the dollar to others at a lower cost, faster, and more securely.