Zelle has instant settlement for banks that use it, including two of the three banks I use.

ACH goes through the FED before it is processed by the receiving bank. Is SEPA sent to the ECB before clearing?

I’ve worked in Fintech for 6+ years. Banks are dinosaurs and the US banks are terrible at adopting new processes/tech.

In the US we are in a standard war with ACH, Zelle, and other payment schemes fighting for market share.