> 1) it has cash back;
That's only a benefit for a small percentage of people. If you're a middle-manager or salesperson, cash back on purchases reimbursed by the company can be considered part of your compensation.
I suppose the bank can negotiate with certain popular companies for a higher cash-back rate, which is harder to do as a bunch of individuals.
Outside of these, it's not really a benefit since it's included in the interchange fee. You might not notice it because your bank hides it with clever marketing, but it's there.
> 2) it has no fee in most cases
One common credit card fee is 2.9% + $0.30.
> 3) the payment is instant for the user, meanwhile bitcoin is much slower.
Payment is 6 months if you want to be sure. Anything less can be charged back. Bitcoin payments are instant if you're willing to immediately confirm, which isn't a bad idea on payments smaller than $50 or where it's a repeat customer.
The one area that you truly benefit from a credit card is in the consumer protection laws: You can chargeback very easily and it's tough for the merchant to dispute it. Bitcoin transactions can't be reversed, so if you get scammed you're out of luck.
The items you've mentioned are just banks out-marketing you. They aren't fundamental benefits. You pay for them with a markup that the merchant adds, and you also end up paying for a bunch of banks and Visa/MasterCard to exist.
Checks or ACH are better than both credit cards and cryptocurrencies, when applicable. Terrible security and a bit clunky, but very efficient for moving money around. And you can even get a card with a lower fee: I think the debit cards from major banks are 0.05% + $0.21, though you might have to convince the merchant to charge you less.
My ruling? For casual use, then - mostly because of the better security:
Credit cards > Cryptocurrency > Check/ACH
For anything serious, then - mostly due to cheaper transfer costs and assuming you can trust the counterparty:
Check/ACH > Cryptocurrency > Credit Cards
For guns, drugs & porn, then - mostly because you don't want self-righteous politicians or outraged soccer moms pressuring your financial processor:
Cryptocurrency > Check/ACH > Credit Cards