Earning a living with bitcoin is not a big deal. Its not possible to run a whole family, but with the earning one can fulfill one or two of the basic needs such as food, utility bills or Clothing.
I even think you can feed a whole family if you have enough bitcoins for it.
You only need the invest a lot in the beginning for sure.
Investing all your money into bitcoins at initial stage is not a wiser decision to make, if the price drops you need to suffer losses, at a moment bitcoin is taking care of extra expenses so let it be extra only.