Maybe it will happen one day that cryptocurrency will be dominant than fiat but banks will stay and fiat will never vanish since not every people has the capability of earning cryptocurrency.

I am not sure that cryptocurrencies will never replace the FIAT currency for any reason FIAT will remain the main currency used by humans in the world.

I think that crypto can not totally replacing fiat, because crypto is concentrated only in highly urbanized areas ,but to rural and mountainous part of the country where in there is limited signal of internet access ,so fiat is still the medium of exchange to be usual in use.

Lets say crypto completely and utterly replaced fiat. Fiats don't exist anymore. All governments have seen the advantage of using digital currency and have completely changed their fiat into crypto, like dollar to dollar token(obviously not tether). How viable is this? For example anyone can see how much I am holding using the public ledger and track me down and force me into sending them the cryptos I hold. I wanna discuss in reality if cryptos actually replace fiat how life will be and what are the problems we are gonna face and the immediate effects of it.   

Lets say crypto completely and utterly replaced fiat. Fiats don't exist anymore. All governments have seen the advantage of using digital currency and have completely changed their fiat into crypto, like dollar to dollar token(obviously not tether). How viable is this? For example anyone can see how much I am holding using the public ledger and track me down and force me into sending them the cryptos I hold. I wanna discuss in reality if cryptos actually replace fiat how life will be and what are the problems we are gonna face and the immediate effects of it.   

it looks like cryptocurrency will never be able to replace fiat, fiat will always be there and the use of cryptocurrency will also remain so that cryptpcurrency and fiat will be used for transactions.

I think fiat will still be there even if cryptocurrencies might become global currencies. Fiat will still be used for local transactions and for daily transactions.