Until it is in prod, it is a proof of concept. Blockchains solve for low trust; if you have trust, you don't need the efficiency loss of a decentralized ledger or blockchain. Central banks provide trust.

As mentioned in one of my other comments, Pix in Brazil costs ~$10M/year. They process ~6-8 billion monthly transactions and roughly $6.7 trillion in payment volume a year [1]. That's roughly ~$0.0015/transaction based on the math in this comment, and we don't know what the ceiling is based on existing capacity (which would drive per transaction costs down further). Choose boring technology, when possible [2].

The innovation in this context is nuking the profits of Visa and Mastercard (their margins are ~45-50% [3] [4] [5]), replacing them with central bank instant payment systems run at cost. The reduction in their revenue is money back in the pockets of everyone paying unnecessarily to move value around. I highly recommend the book "The Innovator's Dilemma" on this topic [6].

[1] https://www.ebanx.com/en/insights/articles/five-years-on-pix...

[2] https://www.elibrary.imf.org/view/journals/002/2023/289/arti...

[3] https://finance.yahoo.com/markets/stocks/articles/visa-vs-ma...

[4] https://finance.yahoo.com/markets/stocks/articles/mastercard...

[5] https://aftabborka.substack.com/p/over-50-profit-margin-how-...

[6] https://en.wikipedia.org/wiki/The_Innovator%27s_Dilemma