With credit cards, you're essentially giving away your private key to random strangers, hoping they will only withdraw (from your account) what you owe them, and not empty your balance, or store your details in some stupid way so hackers will get their hands on it. Hardly needs explanation why this is wrong on SO many levels. Hence the hundreds of millions (at best, probably billions) of annual credit card fraud. And then there's even people saying "yes, but we're insured against that". Guess who pays that insurance. Hint: not the banks or the credit card companies.
That's why fiat have a central authority to try to stop hackers & thieves. If you dropped your credit card in the middle of the street and someone used it, the bank is going to help you. You'll probably get all your money back even though it was your fault.
With bitcoins, you're on your own. If you dropped your paper wallet, no one is going to help you. The same could be said about cash, but that's why I use plastic instead of cash most of the time.