As energy has a usefulness and intrinsic value that even gold lacks. It could be traded anonymously like cash like batteries as dollars or as energy storage and quick and efficient transfers becomes smaller and more convenient. Im thinking specifically electrical energy with batteries and capacitors but even gas could be used.
It could be created by individuals with solar panels or bike mounted generators. It could be stored as potential energy in large amounts as heat or pressure and then converted back to electrical energy when needed. It could be networked for large transfers. There could even be large banks that hold energy as a business, but they would not be able to lend more than they hold. Private individual energy storage would be the most secure from government or other seizure obviously.
Wheres the flaw?
Yes and no. Reread the fed seizing gold from the American people.
The bulk stolen was stored in safety deposit boxes in banks. Keeping your crypto in an exchange, the exchange can get robbed. Keeping it in a hard device, your device can get stolen.
Hacking a password is as simple as torturing someone for a password or pin.