Of course that's how they make money. You don't expect them to borrow it out at the current interest rate and also pay that interest to customers where do you then expect them to pay for staff cost, the facility they ensure they funds are safe, the maintenance of security infrastructures, the cash reserve ratio and the whole of other incidental costs to ensure they amount is safe with them. You don't conclude that one is better off investing in crypto currency just because of this returns what if after the returns, the exchange sites is hacked via insider job, or the wallet itself becomes vulnerable, the coins invested becomes delisted, government itself ban the use of crypto currency in that country etc.
Now, because of how wise customers are in terms of investment decisions, banks are trying hard to increase the interest rate to as high as 10% for some banks, negotiated fixed deposit rate, several promotions to increase saving habit etc. I think for a smart investor, its better to know the right combination of the two.