Will bitcoin become "the motor of the world"? 
Heh, no.But it might become that static motor John came up with before he disappeared.
I still prefer to think of Bitcoin as Galt's Gulch, which we can easily disappear into if we wanted to "exit" the economy.
That's a game changer.
Its not really. Most people don't have cash - they have assets like houses, farms and businesses. A country under server economic duress will always have the option of taxing those assets.