I honestly don't think it'll happen, certainly not in 15 years... In 100 years maybe?
Lol, how did you say that? and how did you know that after 100 years bitcoin will replace dollar. Nobody knows what will happen tomorrow, but there is a possibility to be happen that bitcoin can replace dollar depending on how the people around the world will adopt bitcoins.
Agree with you. Crypto currency is very unpredictable and it makes no sense to make long forecasts. But even if the crypto currency becomes very popular, I'm not sure that it will replace the dollar