Okay, in this universe there's no stable, and essentially we can't assume that Bitcoin will be cryptocurrency's future as technology is changing. In one side, what is now common and most modified will be obsolete in the near future, unless Bitcoin creator keeps up with the advancing technology and has made many changes and enhancements to Bitcoin to remain competitive. Bitcoin itself has many flaws but the good thing about Bitcoin, unlike these altcoin ICO, IEO craze, it doesn't start with crowdfunding, besides being the first decentralised cryptocurrency and widely adopted cryptocurrency.
That's right, we cant assume that bitcoin will be the future of the currency and the cryptocurrency because as time passes by technology around us is evolving day after day in which the technology is so fast on changing in different phases that's why we can't assume that this is probably the future.
Bitcoin right now is one of the trending in the internet world in which it is already become popular due to many of users that are engaging into it and that is the best way we can say that bitcoin right now is good, but until when it will be good enough for us crypto enthusiast? Until the next decade? What if after some years there would be some cryptocurrency that will defeat bitcoin? Then we cannot say that bitcoin is really the future.