It is said that bitcoin will destroy the fiat system but i believe that if this happens the world will change completly because banks and a lot of things will go out of market.
I would find it very hard to believe that by the year 2022 everyone will be using bitcoin. but i also would not be surprised to be wrong, given the remarkable pace at which bitcoin has already advanced. I would say that by 2030 all governments in the world will be holding bitcoin and lightening networks will still allow everyday transactions also.
Well banks can very well adopt btc also so i dont think that if ever that happens, banks will go out of market. And the way i understand this, it not that btc will be exclusively used by everyone by 2022. I think thats almost impossible but everyone may have held or used btc at least once then, thats a higher possibility