Cryptocurrencies is the future, one way or another.
We need to get rid of traditional banking, improve the blockchain process and find a way to block mining, then we are much more efficient than traditional banking because you can easily do thousand transactions within milliseconds without depending on external middle mans.
My idea is that Govt. takes over cryptocurrencies and that traditional banks monitor and improve the system. So you still have your bank, the govt is happy because they can monitor potential fraud and we get a more privacy respecting system.
The entire ponzi scheme discussion only stands and falls with mining. If that is out of the equation then we are pretty much ready to go, China uses their app, so there is no hard cash anymore and it works pretty well for them.