Agree Central banks not necessary.
Ron Paul wrote an interesting paper years ago about transitioning away from the Central Bank system by running a parallel choice of money (not currency) side by side and let the people choose. A weaning off period.
In a way, to a limited degree this is happening w/cryptos. The only faults I see in cryptos is security from hacking (or losing a key or wallet) and the issue of a fixed value, since diluting the amount of money/currency has always historically led to the same problem.
VZ was going to or did come out with a gold backed crypto. I haven't followed up on what happened with that.
Goldmoney married to something along the lines of a debit card?
I don't know the solution. Just know it can't be a chaotic unwind from the current system. There aren't very many people prepared to handle chaos.