Cash still works and if you can get enough people to go back to using it then credit cards will have to change or be more ripe for disruption.
I for one never carry cash, and I will happily pay any extra transaction fees from local businesses for the opportunity to reduce the size of my wallet, the cost/risk of casual theft, and the need to queue at an ATM for cash as part of my daily life.
I use credit because with the rebates it’s rational for me. If retailers offered a sufficient cash discount to wipe out the 1% rebate, I would move most of my volume to debit or even to direct debit.
An example is my cell phone bill. Verizon offers such a huge discount for direct debit that I do it. Otherwise I would certainly use credit.
Ironically, many smaller shops don't support it, even though it would theoretically be cheaper per-transaction, because the up-front costs and hurders are higher than a Square account.
Rinse, repeat with most vendors.
I went to a Chase last week. They didn't have any cash. I filled out a withdrawal slip and finally found a teller. She just told me to use the ATM. I didn't have my card with me. That's why I went in the branch and used the withdrawal slip.
And on top of that there's so many businesses that just refuse to accept cash now.