if i build a bank of bitcoin that operating like a traditional fiat money bank when people can save the money and get interest for their saving and also people can get a loan from my bank but the fiat money is change for bitcoin, the question is would you guys trust me to save your bitcoin on my bitcoin bank that i want to build ?
It defeats the whole purpose of the blockchain which aims to eliminate the need for a third-party consensus in handling every transactions.
The blockchain technology was created for the purpose of putting every transaction in a public ledger which can be seen by all people in a public ledger, which each steps of the transaction being absolute and unalterable. On the other hand, banks have control over the transactions and we create a fiduciary relationship between them in storing our money.
If a bitcoin bank were to be created, there needs to be someone who oversees the transaction, which again defeats the whole purpose of creating the blockchain.