Bitcoin is online currency and bank is money storage offline. I mean it is different, bitcoin won't disappear the bank. But no one knows what happen in the future.
Even in future if we experience digitalization, banks won't get disappeared because of the bitcoin's growth.
Bitcoin transfers are usually irreversible when there is at least one confirmation. This makes it hard for attackers to reverse without controlling significant percentage of the network or a long block reorganization.
Also, merchants can accept Bitcoin with little to no cost or loss. It wouldn't make sense if the merchant only wants to install a POS with Bitcoin integration when there is a large volume. Transactions are verified instantly by nodes when transactions are sent.