A Visa fact sheet [0] claims 276 billion transactions in a 12-month period, which would be less than 9,000 per second, but still an impressive figure.

Fedwire, the settlement system operated by the Federal Reserve, processed 196 million settlements in 2022, each about $5.4 million, for a total of over $1,000 trillion. [1] That would be about 16 settlements per second. Visa handles many more smaller, individual transactions; aggregates and nets them; and uses Fedwire to settle them between member banks.

Bitcoin could be used in a similar manner, handling a relatively small number of larger settlements; leaving other systems to handle smaller, individual transactions.

[0] https://usa.visa.com/dam/VCOM/global/about-visa/documents/ab...

[1] https://www.frbservices.org/resources/financial-services/wir...