The traditional problem with bank-to-bank transfers in a retail, or point-of-sale, setting has been speed. Cheque was about the fastest that could be mustered.
But with developments like UK Faster Payments (which is mentioned in your link) bank-to-bank transfers are getting faster, in some cases instant. And so usability at the point-of-sale is now on par with cards.
In Holland, iDEAL is used a lot for retail purchases. It's an instant bank-to-bank payment option that competes with the card networks.
The equivalent in Sweden is Swish. It too is moving into point-of-sale payments.
As for the US, I suspect that at some point Zelle will pivot into retail point-of-sale payments. At which point the card networks will have a big competitor.
All of this is good news if you are worried about the card oligopolies!