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.
In my own opinion, bitcoin would be used by almost everyone in the year of 2022. I see that bitcoin users are increasing every year because some people are advertising bitcoin or making it more popular, that's why there are so many people who began interested to use bitcoin for them to have a source of income.