It all depends on your choosing, whenever you like the flexibility of having control of your own money, or to have the ability to earn interest from your savings account, I would like to state that each has their advantages and disadvantages. So until Bitcoin becomes a mainstream currency, it is best to use both a bank account and a Bitcoin wallet. Just my opinion. 
there are advantages and disadvantages of both, the best is use bothI like the bank because there is interest
Maybe the bank's regular interest is the only reason people are still using bank accounts. I believe in future there would be bitcoin banks which will pay people interest for bitcoin deposits. It is practically possible. But bitcoin itself value appreciating over time which is more than bank interest.