I'm amazed that we consider same day, and not sub-second to be an improvement in an electronic system these days.

A problem os fraud. The faster the settlement, the faster money can be stolen.

The fix is to slow it down at the egress, not within the system.

> ACH settlement is getting faster.

I have seen a snail move through my garden at a faster pace. If it were 1992, and all we had were 9600kbps, then I could understand the burst all transactions after hours and then do the settle up over night. Suggesting that they are going to have 3 windows each day for settlement windows is a 1999 solution. That also sounds counter intuitive in that at each of those windows their systems will get slammed with orders to process. If they just let each one settle as they come in, then they would spread the load.

I'm really dumbfounded at how either I'm an idiot and just cannot understand the issue, or at how the rest of the world has been snowed over into believing it is terribly complex and takes decades to make incremental changes.

Not the rest of the world. Canada has fixed it. Interac settlement is 30 minutes max, with a $5000 limit, and interbank transfers are end-of-same-day. This is even assuming you have to change banks: there are only five banks, and they're regionally divided. Settlement in the same bank (and their investment arms!) is 30 minutes, even if the money is going to a different person. I paid for my house with this, and the payment was received before we walked out of the room!

It's only America's payment system that's woefully behind.

EFT's with IBAN are instantaneous too, at least in Turkey

The FedNow system coming online in 2023/2024 will clear transactions within a few seconds. These are just attempts to make ACH faster in the interim.