by 2022? in 6 years? Hardly so...
by 2030 - yes, very likelly.
by 2050 - VERY sure. Not even small doubt. FIAT will be found only in the history books by 2050
Maybe it will used by everyone in the date the bitcoin is widely use in that time. we assure we can found in history in our future user of bitcoin if that happen it nice to heard bitcoin is one of the popular and use in that year.