It would defeat the purpose of Bitcoin if it replaced Bitcoin. Since it would be built on top, it's just a service on a cryptocurrency foundation instead of wh

It would defeat the purpose of Bitcoin if it replaced Bitcoin. Since it would be built on top, it's just a service on a cryptocurrency foundation instead of whatever your government prints. In that case a credit/debit card could basically be an immediate guarantee of payment (3rd party guarantees, collects small % to cover abuse/running costs. basically credit cards now, minus chargebacks), as opposed to what Bitcoin provides.