One thing with the banking system is that they can be bankrupted by just simply filing a chapter 7 or 13. And not just that, if there is an economic turmoil, the banks can simply stopped all of the withdrawals to delay the panic of depositors upon doing batches of withdrawals.

Whilst for Bitcoin, it is in our hands except those that are deposited in exchanges and that's in the same situation in the banks.

But if we're the one who's holding it, we hold our wealth and there is no third party intervention and we're free to move it in and out anytime we want to.