You are actually holding digital gold, not digital money which also needs constant maintenance to keep functioning (gold, for all its disadvantages at least doesn't need miners that keep mining just for gold to keep existing).

Like with gold the currency properties just aren't there. You would need to create the same financial constructs as with gold to add those properties. But would you want let entrust your Bitcoin to a custodian so you could use a Bitcoin backed currency? Not your keys, not your coins.