The only reason anyone would use bitcoin over a credit card or paypal is for tax evasion. For the average consumer, credit cards provide so many advantages that bitcoin really isn't competitive.
Please, tell me more!
Do you mean criminal interest rates?
Do you mean absurd charges, surcharges, convenience charges, annual fees, international fees etc?
I spend tens of thousands on credit cards yearly, and don't pay any of those things except international fees if I leave the US. As for interest, I've never paid any, since I pay off my bill every month, so I wouldn't know much about the interest rates.
Also, I get 1+% back on all my transactions, transactions are instant, and I'm protected from fraud. With bitcoin, there's an enormous risk of being scammed, the software is clunky, I have to wait hours for a few transaction confirmations, and my bitcoins can be stolen fairly easily.