Dollar will be there. You need a dollar to scale/calculate your Bitcoin value. Both could be the same in terms of popularity. But I do not think Bitcoin will take over the dollar anytime soon. Do we expect it? I don't know. But where there is a good side, the opposite exists as well. But we don't know the future. You could be right as well.
Bitcoin can not only be scaled or calculated in dollars, but can also be calculated in any fiat currency so that Bitcoin can continue to be popular on its own without having to depend on fiat currency. And Bitcoin may not overtake the dollar any time soon, but as more people start to feel more comfortable using Bitcoin in various sectors they will need to. Maybe dollar users themselves will prioritize Bitcoin over dollars so that dollar use can be reduced compared to Bitcoin in countries that have legalized Bitcoin, such as El Salvador.
The dollar will remain in El Salvador and the bitcoin will be used by whoever wants to use it, and it is true that bitcoin is not affected by any fiat currency. But I am sure that one day bitcoin will overtake the dollar, because bitcoin is hope and bitcoin cannot be avoided.
If this works in El Salvador, the future of bitcoin is beyond doubt. El Salvador is a real case study for other countries and companies. If I were a citizen of El Salvador and had a business with all its fluctuations, I would be happy to use bitcoin transactions because the benefits are very real. I hope that one day my country will also follow the steps forward like El Salvador. Since I believe Blockchain Technology is the future, all governments should invest in this new technology better than later.