Bitcoin will change the world, in some way it has already.
But it will never be the global cryptocurrency just because it is too slow and too resource intensive. If u look right now, only a small amount of humanity have invested in Bitcoins and some altcoins. Now think that the rest of the world are getting into it. Bitcoin cannot handle it. Maybe some other coin with an other technology can do it.
I think cryptocurrency at all will change the world definitely.
I agree with you. Bitcoin can be considered as the pioneer of cryptocurrency market but we still don't know if it can continue its status as number one cryptocurrency in the next few years. So it is not essentially the bitcoin that will change the world but, as koeb88 said, cryptocurrency can do.
Bitcoin is the one which has brought very big revolution in the world economy and the methods of investments. Bitcoin has changed the traditional methods of investing into different potential things in order to make good profits.
Bitcoin has even turned useless unemployed people of society into employed ones because they keep holding bitcoin for long time. In short, bitcoin is the best invention of this century.