I think that the bank is necessary, but I'm not sure that at this moment with such a specific market, you can expect a confident growth. Rather, it is a project with a riddle to the future. I expect growth by the end of next year.
No. it's not necessary, with crypto having wallet means you become your own bank without the need of centralized organisation to save up the money for you and deducting it for fee.
Also it's against decentralized ideal we have, cryptocurrency was aimed to become a decentralized currency so there's no authorities behind it.