I believe Bitcoin would maintain its dominance for a long time I can't predict what would happen in the future but with the present state I believe Bitcoin will maintain it's dominance. And from your question on bitcoin's role in a changing Economy I don't think Bitcoin can help amend as full as the economy of a country unless they are approved by the government and also administered a post in the economy for an example the way America has made it so large and also administered it that is the only way it can have a role to play in an economy else it would just help few individuals and that alone doesn't play any role in the economy.
First and foremost, lets understand what an economy is all about, then i we explain further on how Bitcoin can positively boost the economy of a nation if adopted as a reserve, even as many nations are proposing a Bitcoin strategic reserves.
Now, an economy consist of production, Consumption, distributions, It also includes, international trades and Government.
Again, it is a system that is inter related with production, consumption and exchange activities, which also determined how nations resources are allocated among all participants in the country.
For example, a Bitcoin reserve kept for certain periods in the future can be used for production of good and services that will benefit everyone, that is, the end users or consumers etc.
In a nutshell, Bitcoin can help every citizen if it's returns are well distributed to the sectors of a nation economy, especially the areas that needed urgent attentions.