But the states will not allow it. States always support systems they can control.
I think that's far from happening. Just imagine how many bitcoins are there, and if billions will be sharing it, then everyone will be getting a few thousands satoshi. It's not that the state wants something that they control, but it's all about the ease, and what's good for their economy. Bitcoin could help the economy, but as a currency of a certain country, it's hard to happen, but in banking, it is possible.
Yes it would be a dream to expect something like this for the next 5 years. But a country like Liberland has accepted bitcoin as its official currency. It would be funny to wait for developed countries to accept such a thing.
But with technology everything changes and changes very quickly. After 50 years, maybe bitcoin can be used by half of world population.
States may have accepted bitcoin. 50 years is enough time for such a thing to happen.