This is my opinion.Banks won't make you rich.saving in bank can never do that,because of interest rate that bank gives you is too tiny.You saving will be simply be eaten up by the sleepy monster called inflation. As a example I will take ,When I'm in grade school,each day I received 10Rs (my country currency) from my mother.It was enough to by me 2 meals,but in now 10Rs enough to buy 2 candies. 
Banks are just for keep your money safe! 
Banks are just for keep your money safe! Yeah you have a point, bitcoin is only a platform which you can save your money. Yes, there's an interest but it is not so very big unlike in bitcoin you can invest your money and also you can gain a lot of profit. In that, they will gain money or bitcoin and there's a lot of people now become roch becaise of bitcoin. Bank is only for those people who only wabts to save and to keep their money.