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.
Bitcoin will not destroy the fiat but will be an alternative currency in the future. The users of cryptocurrency will increase but the percentage of users will vary in every countries exposure to internet. The utilisation of cryptocurrency as a means of exchange will mostly concentrated in the City where most business accepted legit cryptocurrency as payment.
Yeah Bitcoin will not ruin the fiat system, instead, this will just be a new form of medium for trading. The expansion of use and acceptance of bitcoin will always be depending on the business owners, I believe. Going back to the topic, based on my observation and studies, bitcoin will continuously be used by majority of the world population because of the non stop improvement of technology and the convenience and profit it hands to the bitcoin users and investors.