Electricity is clean and readily available. But what if the grid is disrupted?
Digital currency is quick and ubiquitous. But what if the grid is disrupted? What if the controller of the system decides to disenfranchise you?
The multitude of energy sources which are available provide strength, stability and insurance against a single source failing.
Paper currency is not subject to black-outs, computer failures of central office fascism.
You should not put all your Eggs In One Basket.
Neither should the government and, by force of law, society.