Bitcoins will never replace fiat .this type of technology is far ahead of his time .and people should 20 percent of their income in bitcoins which will help in the future.
I am sorry but I disagree with you. Becouse I knew some people country are change their fiat in to bitcoin to avoid government control, it is proof that bitcoin have a chance to replaxe fiat.
If we're going to use "some people" as a proof for something, then we can say that the flying spaghetti monster religion will take over Christianity because
some people were a Christian before and then started to follow the flying spaghetti monster religion. What has happened to those "some people" doesn't guarantee anything for the rest of us. The majority of people are still loving fiat and that's much better statistics than "some people".
People can do whatever they want. They wanted to convert their fiat into bitcoins so there wouldn't be tax or any government control and so they did. The rest of the people would also do whatever they want. Some might even like to use fiat because bitcoin isn't accepted in most places.