First of all, with the current population of the earth not everyone has INTERNET connection, and about only 3 B people are able to connect.
It'll take more than a decade before people begin to use Bitcoin as a necessity. Sure the revolution for cashless society has began, but banks wll eventually see a way to change the tides.
it'll take a longer time than that before the everyones uses digital currency, or Bitcoin for that matter. And we don;t know, someone might outperform Bitcoin by that time.