I don't believe that the world will become so "digitized" as you describe it.What about the poor countries in the third world?Do you think they will become "digitized"?However,to answer your question about what comes after bitcoin.My answer is...nothing. 
The blockchain technology might be adopted in various industries,but all cryptocurrencies will become obsolete.
The blockchain technology might be adopted in various industries,but all cryptocurrencies will become obsolete.
I believe that the world will be digitized. But it will not happen overnight. Remember development? Though each country have their own pace on how fast or slow they will develop. Third countries, or worst than third countries will cope up. Communication is fast so knowledge distribution will also be fast. And once cryptocurrencies become obsolete, that means the world is already in a far more advanced digital era.