That seems an overly fine line to draw, when a check is basically just a plain piece of paper with your ACH number printed on it, and anyone with your ACH number can go get checks printed. A credit card is also bidirectional, so the question was just if alternatives exist to VISA processing, not if you necessarily would use them. I meant to mention Zelle and Plaid too, since they integrate with many (most?) banks already to allow transfers via your online account login authentication credentials instead of traditional ACH