A key reason for the cost of the CC payment infrastructure is that these costs were instrumental in solving the chicken/egg problem of adoption by ensuring that there's enough money/kickback/etc for all the infrastructure partners to market cards and offer various benefits to get both the cards in the consumers pockets and also terminals rolled out at merchants. Noone wants to take the risk to transform crypto into as convenient a service as credit cards because crypto is decentralized enough so that no organization can feel sure that they (as opposed to everyone else) will see enough payout (e.g. lucrative lock-in, skimming part of every transaction) to justify the quite immense and risky long-term investment required to push consumer adoption.