Controlling your keys (yes this implies a backup, all wallets guide/help you to do it these days), having access to the source code of your wallet, and being able to verify the data of Bitcoin's public and open blockchain is obviously much better than blindly trusting your bank and getting cut off from your assets at any point through NO fault of your own.

> Until your keys are lost or compromised. Then you are irredeemably screwed.

Yes, you have discovered the big secret everyone in crypto is "hiding"... when they say self-custody they very sneakily imply you, yourself, have custody and responsibility of your assets. If this NEW digital option is not for you, don't use it, go trust custodians. Before Bitcoin you had no such choice.

In the case of banks you are also pretty screwed... just slightly less iredeemably in some cases... in the worste cases you might need to find a lawyer willing to help you, depending the amount it might just not be worth your time or the time of lawyers/judge. Unless the bank decides to hear reason magically or gets tired of your nagging like in OP's case... seem like a lot of trust and no control at all, at any point.