Cash is king
When you think about it, banks are robbed on an almost daily basis, compared to the days when a bank robber had to get dressed, nick one of his wife's stockings then go outside the house and either blow a safe or bang on the windscreen of a rolling piggy bank to get his hard won loot.
Now all they need is an internet connection and a pc.
I am no fan of the notion of digital currency, for a number of reasons.
Aside from security, privacy is likely to go right down the drain, unless there will be guaranteed methods to provide anonymity, I'll be trading veg, almonds and figs for my shopping as I grow them anyway.
Having worked in banks, including actually inside some vaults, breaking into one if you have the tools is not difficult but doing it rapidly and getting away with it is not trivial, whereas cracking a digital system requires no personal presence and can be carried out at leisure.