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.
It will be used a lot, yes. But not by everyone for sure, because people still will be afraid of bitcoins, not everyone know about bitcoins yet, so it will take more time than that
The major reason is people are afraid of investing their money into it as there are many scammers around who are constantly busy in running away with the money of people so I don't think it will be used by everyone in future.