Can bitcoin take Fiat's place in time? Suppose it does? Can govetment step in and stop this program?
I don't think bitcoin can take place of fiat currency . The government will never let any loss happen to their currency through some other digital currency . Bitcoin can totally change the economy of a country by making it
decentralized . Moreover , government will not have track on any of the transactions and activities of the users i.e they can't let bitcoin take place of fiat money.
Maybe you mean centralized? Bitcoin is a decentralized stuff which means controlling it over will really be impossible but somehow can really be slowed down.Thinking off there are lots of services which bitcoin is involved which government can possibly impose taxes on the users of it.This is the only way they can milk out some tax into bitcoin. Frozen thing is not possible as long theres a good and strong community support on it.
We do already witness on the things been done by the government. Banning, regulating ICO and other related things but still bitcoin is standing strong.