If we talk about crypto and paper money it's not about who will stay alive, because they are for different tasks. Untill there are people on Earth, they would always need a touchable, energy-free and off-line equivalents, like paper money, gold, diamonds, whatever. Crypto is a strongest threat to Visa/Mastercard/AmEx and whole centralised financial system as well. It happens because of fantastic success of cryptocurriencies during all last years. So I would rather belive that cryptocurrencies will replace digital currency and bank centralised system.
That's actually a really good point. I didn't think about energy-free/off-line uses..which is a very real possibility. Thanks for bringing that up!