It would need to be a concerted effort, imo. Not just one or two actors. But if enough market share made the move, the benefits? Numerous. As I already outlined

It would need to be a concerted effort, imo. Not just one or two actors. But if enough market share made the move, the benefits? Numerous. As I already outlined, in my OP. In addition, to what I said, the (new) market would cut out all middle men (Visa, etc...Chase/BoA, etc...maybe even others). I think some downsides would be more or bigger insurers and maybe an aggregate of wealth but even our current system doesn't tackle these issues. No system will be perfect in the first increment but I think this would be a step in a better direction, for all involved.