Your money in the bank is just a number that shows the amount of balance you have saved, it is your money, but it is not entirely yours because the bank has access to manage the money. If you keep it in a small amount to make it easier to make buying and selling transactions, you may still be able to bear the risk if something happens to your bank account, such as a break-in or your account is suddenly closed. Make your bank account a temporary transit place when you make a withdrawal from the Exchange, after that you manage the money yourself to avoid any risks that may occur.
Our money in the bank is just a number that represents the amount of money we save there, so there is a report according to what we save, it is true that we do not manage it but entrust the banks to keep money in their vaults, like that concept with certain conditions and requirements that you have to do to the bank.
Therefore I have never kept all my money in the bank because it is not us who control it, if they collapse and there is no liquidity to make withdrawals then we cannot withdraw our money from the bank, so save the money we only need for needs if we cannot save it ourselves, and the rest can be saved in bitcoin or money that we can manage ourselves without third parties.