Jack Dorsey might be right to some extent, but I do believe we shall be having a few more other coins by the later part of the next decade. Blockchain is sparking innovation across various industries and there are more opportunities waiting to be explored... all these having various coins that are being used.. Just like steem which is having steemit progressing at a fast rate. The world is starting to fall for blockchain technology in various fields since it provides visibility, efficiency, low cost payments and much more that is not found in other solutions.