First off you're right to be worried, but for laughably wrong reasons.

Banks no longer necessary. Ha. They will always use their power to preserve themselves. They own the government. Banks will exist forever. Banks going away would be a financial holocaust.

Secondly, you left off the two really bad things you should be worried about.

Working means they're good at robbing you through inflation and all kinds of nickel and dime shit.

Failing is when they work so well that the people benefitting from the inflation (billionaires) make it inflate more and more.

There's countless other ways CBDCs can and will fail. Government corruption is guaranteed. Good luck getting any government to create a system that it can't itself control. CBDCs will always be as draconian as possible. Strict names attached, controls, bans, seizures, thefts, guaranteed inflation, foreign attacks, sanctions, etc.)

Good luck making a system that China isn't going to attack constantly. When they reboot the Die Hard series, they're definitely going to attack the US CBDC building. Or Mission Impossible, or 1000 B movies shot on iphones.

Imagine Grub Hanser walking into a secure building looking like a tourist. Guard: "You can't be here." Grub: (in bad American accent) "Oh shucks. I mussa gotta turned around." *Blows away single solitary guard. *Turns CBDC off and on again and resets everyone's to zero. *(steals all of the money).