In the interm there's been unfortunately little progress. Zelle is supported 'natively' by all major banks, although it has horrible UX (starting with "each bank is different"), and allows for pseudo-instant transfers of small amounts (up to $x,000) between individuals in the US. (It is instant for the user, but on the subject of replacing ACH, it's more correct to say that it's pseudo-instant, same as credit cards - it seems instant to users, but until ACH is replaced, settlement will still happen in nightly (possibly half-day-ly) settlement batch files.)

It's mostly functional, the problem is that it doesn't work for anything more than trivial amounts, for various reasons, so the choices are either to wait 2 days, or physically walk to a bank location, authenticate, get them to give you a magical piece of paper, and then walk to the other location. (And then sometimes you still have to wait a few days more if it's not something you normally do "while the check clears".)

It's a byzantine system, but at least it doesn't (as a customer - it still does in places on the backend) involve me having to find a fax machine to send a fax, or send a picture of a check through a sketchy "free" online service.