Perhaps, but can Indian expats also send money to India via this gateway? Can you use it to order something online from another country? What about the relative weakness of the Rupee vs a mix of reserve currencies?

Libra still makes sense as an "international" currency, even if it doesn't make sense nationally.

> can Indian expats also send money to India via this gateway?

Not yet, but I've heard that this is in the works. The hardest part of trying to use UPI right now as an Indian expat is that you need an Indian phone number and your bank account should be linked to it.

You are vastly overestimating the sophistication of the US banking system. Integrating with it is incredibly difficult since so many steps rely heavily on trust between parties. For example, information sufficient for direct depositing into someone’s account is sufficient for direct depositing OUT of said account as well.