It also tends to present a piece of info to identify itself, so that you know it's not just something utterly random. It's been superseded in a bunch of ways,

It also tends to present a piece of info to identify itself, so that you know it's not just something utterly random. It's been superseded in a bunch of ways, but it cut down on fraud, so it has been useful. That's the only metric the payment network participants really care about. Perfection would be great, but as long s there are results, they're good with it.