It wouldn't work /for you/. But for people who do answer their phone, it would add protection.

Possibly but you'd want to be damn sure it was actually the bank calling you. What's to stop a scammer claiming to be from the bank calling you.

"Hi I'm from bank xxxx calling to warn about some potentially fraudulent transactions we've detected on your credit card before we can continue please answer a few security questions to verify your identity."

I suspect some people would fall for that and tell the 'bank' their personal details.

I've yelled at most of my banks for cold calling me exactly like that. My response is, "Can this be corrected online? Otherwise, I will call the 800 number myself and if you could provide any specifics that might speed up that next call I would appreciate."

In the past I've also sent letters to bank security teams not to cold call and ask for personal details.

One of my banks actually switched to a standard recorded message that ends in a "Please call our 1-800 number at your earliest convenience." Better.

A text message / email might though.

Just saying "Your account has been flagged for a lost/stolen phone which you use as your 2FA. Please contact support if this is not correct."