is bitcoin more popular than US Dollar ?
Not yet, but may one day.
Yes it is sure that one day bitcoin will be more popular than USD because of the increasing demand of bitcoin with the passage of time. It is obvious that the demand of bitcoin is higher than USD but the problem is that not much people know about bitcoin and if they will know about then they will have only bitcoin for their use.
How is the demand of bitcoin greater than USD when USD is more popular than bitcoins? You might see that there is an increase in the price of bitcoins. Because the demand is good, but when you compare the demand to USD, it's nothing. By just looking at the number of Americans that need the USD, it's obvious that bitcoin is still nothing.
I really doubt that bitcoin will one day be more popular than USD since almost everyone knows about the United States and, thus, they know about USD. Even when bitcoin goes mainstream, it will be just a thing on the Internet and those people that don't have access to the Internet and the people that don't like technology that much will never know about it.
choppork it is a possible thing to happen, right now we are living on a world the relies heavily on the internet. And recently the people who became billionaires relate their products to the internet/web ( Facebook, Snapchat, UBER to name a few who became successful with their products related to online). Now can you imagine a world that has one currency that can be use to transact with everything online? Bitcoin may be the possible solution for having a one currency that will be use with internet transactions. Who know it might end up being use by Fb and UBER with their payment methods. If we believe in Bitcoin we must support it.
You can surely imagine all those stuffs but almost everything that you imagine without conducting research about it is merely an imagination. Yep, we can surely live in a world where there's one currency. But the question is, is this realistic? Will the government allow this? I hardly think so. There's just far too much contradiction in the world for the governments to come up with an agreement most especially that it's money related. When money talks, everybody becomes serious. Every government wants to get take advantage out of it. And since bitcoin leaves the government out of the picture, I really doubt that they are going to push themselves in it.
Maybe they can create their own universal centralized cryptocurrency but will only lead to people loving different cryptocurrencies instead particularly the decentralized ones.
All of your example can become true except for the "a world with just one currency". Every service that are connected to the Internet (or at least using the Internet) will surely adopt bitcoins when it goes mainstream. Even just establishments like coffee shops and whatnot might accept bitcoins. But a world with just one currency is far from reality, if you ask me.
