Why doesnt the government control the banks?

Why doesnt the government control the banks? I always hear how banks control the government decisions. Also that Rothchilds and all these elite families involved with banks control the world. Well how come the government doesn't step in and take control of the banks then? If 90% of money in the world is own by selective families how come the goverment doesnt come in and take the wealth and use it for funding and **** like that, how come they have so much money? I hear that it is because they control the banks so the government should control the banks get the money and use a portion for funding then they could lower taxes right. So they control the bank, use a portion of the money to create jobs and what not then everybody wins. Its not like the banks will ever run out of money because people will always be putting money in and taking it out. I am confused about this. Hopefully somebody understands me.