It is too soon to tell as bitcoin is still in its infancy stage
and has yet to become mainstream and adopted by the
public.
I don't think it will replace fiat currency in at least 10 years
or more. We still have a lot to achieve and I believe this is
only the beginning of a revolution.
I agree completely. In time fiat will be replaced but scaling will take time and different ideas will be molded and implemented along the way. We will just have to wait and hope to live long enough to see what the finished product will be.