Paper money is more durable than electronic money. Obviously, you cannot accept electronic money any place that is not specifically set up to take it, or when power or internet is out. I'm not sure you'll ever eliminate physical currency for that reason.
Along that line, there would be a strong incentive to be able to hack and manipulate a foreign nation's money supply since they would have no physical currency to fall back on. It would almost guarantee that nations attempt it as an economic warfare contingency.
Well yes but remember most nations have a gold reserve too.
But i feel the need for paper money is ever lasting. I don't see it dissapearing any time soon.
People need fiat since not all shops will accept e-money.