Hello there,
I admire your effort put into this.
First of all,I do not agree on the efficiency of cryptocurrency especially Bitcoin.Credit cards,in this case Visa do process 2k tx/sec while Bitcoin 3tx/sec,that's a huge difference.So yeah I think Bitcoin is really not efficient in terms of transacting.
Second,I don't think that crypto are more secure than credit cards or credit cards are more secure than crypto.Simply because both of them depend on the user's awareness of security.If you purchase from shady websites online with credit cards you should expect get hacked nope?If you let your private keys/seed unsecure same thing would happen.So yeah,it's users responsability.The difference is that banks have always a team that 24/7 monitor the transactions.So in case there is fraudulant transaction they block the card or you call them to do so,while in crypto if you are stole,it's gone forever.
Regards