While I do agree for other reasons, the problem you state can be solved by being paid with bitcoin. Some employers (notably, police) do have the option to pay wages in bitcoin. Though these are very few they are still there.
yes it is looking difficult but i think in future when all the people of the world will reject fiat and will start using bitcoin then it will become possible that bitcoin will replace fiat.
Don't dream mate, and it's not possible. Bitcoin will never replace fiat. If the Bitcoin may accept by governament, and it will become legal currency, but it never replaces fiat currency. Without fiat currency, the govt can't run the country. And if the allow the only bitcoin the revenue will slowly decrease, and the govt will face a lot of problems, so they will not allow only Bitcoins.