haha you youngsters don’t know about this, but for a time US banks had “bank cards” as well that you could use with point of sale and “credit card” machines… this was before MC/Visa got their hooks into the US bank card game… but basically US “debit cards” are the only bank cards in the world that are tied to the MC/Visa networks… in literally every other country in the world, bank cards operate on their own networks… in Australia its EFTPS and in Canada its Interac… and these operate under EMV specifications for RF performance and communication protocols, but they have nothing to do with “signature networks” like Mastercard and Visa… and I don’t believe my RBC bank card expires either.
The one risk / down side is that they are super quick to deactivate a card for just about any reason… and yes you can only have one at a time… but if you can manage to get one converted, it would be a viable option for an implant that could have an extremely long life. Not indefinite, because there are other factors like security events or algorithm end-of-life events that force card swaps for customers, but those are rare.