One day banks will accept Bitcoin as medium of exchange and accept deposits from bitcoiners. As soon as the world powers accept it as medium of exchange.
Why would you want to send your Bitcoin to a bank when Bitcoin was literally created to work without banks and third parties?
Even if they start accepting Bitcoin they would not allow you to withdraw whenever you want, they would charge additional fees, they would force you to use their ''approved'' wallet, and other crap like that.
I agree with @dkbit98 because if bitcoin is put into a bank, the essence of the coin's freedom will be lost, what happens is a kind of digital version of an account but using conventional rules (bank), so far we have full access to the private key and we have full sovereignty over what assets we have, but if it has been handed over or saved to a bank, it means that we also really monitor what becomes our assets, in fact often the bank's rules are on us, while other bitcoins open up freedom to their users or those who own them, so I clearly think that keeping bitcoin yourself means we choose true freedom, which is not subject to the system (bank rules)