For the big country like Japan and USA, i think paper money will dead and digital money will take it. But for developed country, i think paper money will be used permanently.
I think you mean undeveloped countries which can't afford to set up the digital money system. For all other countries which can afford setting it up, digital money will be their only option.
i guess you are right and it is really good to be honest, it is really good in my opinion because the financial system we have is really falling