There are no problems with digital currencies. We should abandon fiat altogether.
That's a bit radical and knowing the current state of living in almost every country, total abandonment of fiat is going to be impossible, how would the impoverished people exactly buy the needed tech to use for storing their wallet? Even if the government gives them which is unlikely to happen in third world countries, impoverished people are technologically illiterate so there's an unlikely chance that a what you're proposing could be successful right now.
Yes, impossible. Not getting rid of that fiat entirely would be a mistake. Internet and smartphones are very common these days but not everyone can use them. My parents still use Nokia 1200 now, How will they live if fiat is abandoned?. Digital currency or cryptocurrency is only suitable for young people. may not apply to everyone.