So lets say bitcoin is eventually gonna mean the downfall of the bank
as a wallet is basically a bank. You can store money and make transactions all freely and
autonomously. Theres even coins like populous that aim to make it possible to borrow money from crowd funded pools instead of getting
it from the bank or having to search for an investor who'll definitely take his share.

So when that happens and the banks and the government can't cooperate anymore. And the majority will be payed by bitcoin and wouldn't that
force governments to also start using bitcoin (or any other crypto currency but it wouldn't really matter to much as bitcoin is like the backbone of every coin) which would naturally mean that their own currency will lose its value by the amount that the government choses to use the bitcoins instead. And lets say one day theres not much fiat left ... how would the value of a bitcoin measured? in Eur USD Yen?

Or will it ever even come to such a scenario?

Just really wondering