Is it solely on the bank to decide whether or not to waive off interest if delay in credit card payment?

Yes. The onus is on the banks. Can't help it. CFPB has requested banks to take debt relief measures for the clients.Many banks and credit card companies have already offered various types of debt relief programs. Most of them are not charging any penalty. So, I feel you should contact the bank first and find out what they are willing to offer you. Consider bankruptcy as the last option. But yes, you can file it if you want.

You should consult a banruptcy attorney for help.

Well, many credit card companies are offering some sort of relief like lowering interest rates, allowing nonpayments for some months to support their customers who are going through financial hardship during this pandemic. However, there is no government order regarding credit card debts.
Secondly, I would request you not to think about filing bankruptcy now as it's the last resort to pay off your debts. rather, talk to our expert financial coaches at 800-DEBT-913 to get instant help about credit card debt.