Bitcoin can be the future bank all over the world. It might be similar value of World Bank.
Now a days there are so many big transactions are done with crypto currency. If people dont want to tell globally about their transactions they may use crypto in big number of amount in a single transaction, and nobody else can recognize that why and what they do transfer.
If there any kind of illegal activities involved in that transaction then if there is bitcoin bank exist over there then some kind of transactions may be stop by the bank.
In that case all the government make bitcoin bank in future, they will ask for all accounts details and the person who access the account. If all holders gives them details then it will be it safe or not?
very unlikely, because basically bitcoin uses peer to peer networks to operate without authority and bitcoin is a source of decentralization that cannot be controlled by the central organization, and even if the government makes a bitcoin bank in the future in my opinion this will be very complicated for bitcoin users because they will definitely ask us to do KYC or AML so they can limit our bitcoin and collect taxes with our bitcoin.