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.
But the world are digitized already?For how many years since the computer was created the world started to become digital and before cryptocurrency arrived we are already digitized so whats this question is all about?but bitcoin may help the whole world making rhe payments totally digital so in future fiats will not be needed and cryptocurrencies will took overs.maybe somehow but maybe not