This is very possible. The Blockchain technology is a revolutionary one with a lot of significance. As the people become more familiar with it, the adoption and utilization of the Blockchain and cryptocurrency will increase which will gradually lead the world to cashless.
No, the world will not be digital in the foreseeable future. Not everything can be made digital. We already have digital television, digital photo and video filming and many other useful innovations. The world is moving towards the introduction of digital technologies, but they can not be used everywhere. Its application is limited. Try growing digital food or living in a digital home. Surely, you will not succeed.
Cryptocurrency will also not be major in financial relations. It can only be an addition to regular currency.