It can be both, the plumbing is straight forward, simply a matter of will to implement. UPI in India, Pix in Brazil, FedNow in the US, etc. Trimmings are things like paying via QR code and alias support (phone, email IDs). Pix had native alias support, Wero is alias support on top of SEPA Instant payment rails (with a ~ten second settlement SLA).

This gets you to utility cost recovery fee structures and sovereignty over your payment infra, versus other countries controlling your value transfer capabilities.

https://en.wikipedia.org/wiki/Instant_payment

https://en.wikipedia.org/wiki/Wero_(payment)

https://en.wikipedia.org/wiki/Single_Euro_Payments_Area

https://www.ecb.europa.eu/paym/retail/instant_payments/html/...