great observation - I believe that for real-time clearing between bank customers there are about 2,000 banks and credit unions connected to Zelle and for settlement between these banks, Zelle uses the mix of systems you list. It's a feature of the large number of banks in the US and the mixture of direct and indirect participants of the 12 regional Federal Reserve Banks where settlement occurs.
What I find interesting with Zelle is that it doesn’t have its own rails, rather it’s using a mix of ACH, Visa Direct/Mastercard Send, and RTP
great observation - I believe that for real-time clearing between bank customers there are about 2,000 banks and credit unions connected to Zelle and for settlement between these banks, Zelle uses the mix of systems you list. It's a feature of the large number of banks in the US and the mixture of direct and indirect participants of the 12 regional Federal Reserve Banks where settlement occurs.